Replaced lists containing unique values with HashSets

Reworked Soft Insert id checks

Improved dogtag id lookup memory usage

Removed wave cleanup code

Libraries/Core/Callbacks/ItemEventCallbacks.cs

@@ -32,7 +32,7 @@ public class ItemEventCallbacks(HttpResponseUtil _httpResponseUtil, ItemEventRou
         }
 
         // List of non-critical error codes, we return true if any error NOT included is passed in
-        var nonCriticalErrorCodes = new List<BackendErrorCodes>
+        var nonCriticalErrorCodes = new HashSet<BackendErrorCodes>
         {
             BackendErrorCodes.NotEnoughSpace
         };

Libraries/Core/Controllers/HideoutController.cs

@@ -250,7 +250,7 @@ public class HideoutController(
 
         // Dont inform client when upgraded area is hall of fame or equipment stand, BSG doesn't inform client this specifc upgrade has occurred
         // will break client if sent
-        List<HideoutAreas> check = [HideoutAreas.PLACE_OF_FAME];
+        HashSet<HideoutAreas> check = [HideoutAreas.PLACE_OF_FAME];
         if (!check.Contains(dbHideoutArea.Type ?? HideoutAreas.NOTSET))
         {
             AddContainerUpgradeToClientOutput(sessionID, dbHideoutArea.Type, dbHideoutArea, hideoutStage, output);

Libraries/Core/Controllers/InsuranceController.cs

@@ -733,9 +733,8 @@ public class InsuranceController(
      */
     public void InsureSoftInserts(Item itemWithSoftInserts, PmcData pmcData, InsureRequestData body)
     {
-        var softInsertIds = _itemHelper.GetSoftInsertSlotIds();
         var softInsertSlots = pmcData.Inventory.Items.Where(
-            item => item.ParentId == itemWithSoftInserts.Id && softInsertIds.Contains(item.SlotId.ToLower())
+            item => item.ParentId == itemWithSoftInserts.Id && _itemHelper.IsSoftInsertId(item.SlotId.ToLower())
         );
 
         foreach (var softInsertSlot in softInsertSlots)

Libraries/Core/Controllers/InventoryController.cs

@@ -261,7 +261,7 @@ public class InventoryController(
 
         var foundInRaid = openedItem.Upd?.SpawnedInSession;
         var rewards = new List<List<Item>>();
-        var unlockedWeaponCrates = new List<string>
+        var unlockedWeaponCrates = new HashSet<string>
         {
             ItemTpl.RANDOMLOOTCONTAINER_ARENA_WEAPONCRATE_VIOLET_OPEN,
             ItemTpl.RANDOMLOOTCONTAINER_ARENA_WEAPONCRATE_BLUE_OPEN,

Libraries/Core/Generators/BotEquipmentModGenerator.cs

@@ -41,6 +41,18 @@ public class BotEquipmentModGenerator(
 {
     protected BotConfig _botConfig = _configServer.GetConfig<BotConfig>();
 
+    protected HashSet<string> _modSightIds = ["mod_sight_front", "mod_sight_rear"];
+    protected HashSet<string> _scopeIds =
+    [
+        "mod_scope",
+        "mod_mount",
+        "mod_mount_000",
+        "mod_scope_000",
+        "mod_scope_001",
+        "mod_scope_002",
+        "mod_scope_003"
+    ];
+
     /// <summary>
     ///     Check mods are compatible and add to array
     /// </summary>
@@ -152,7 +164,7 @@ public class BotEquipmentModGenerator(
             // Choose random mod from pool and check its compatibility
             string modTpl = null;
             var found = false;
-            var exhaustableModPool = CreateExhaustableArray(modPoolToChooseFrom.ToList());
+            var exhaustableModPool = CreateExhaustableArray(modPoolToChooseFrom);
             while (exhaustableModPool.HasValues())
             {
                 modTpl = exhaustableModPool.GetRandomValue();
@@ -454,7 +466,7 @@ public class BotEquipmentModGenerator(
         var randomisationSettings = _botHelper.GetBotRandomizationDetails(request.BotData.Level ?? 0, botEquipConfig);
 
         // Iterate over mod pool and choose mods to attach
-        var sortedModKeys = SortModKeys(compatibleModsPool.Keys.ToList(), request.ParentTemplate.Id);
+        var sortedModKeys = SortModKeys(compatibleModsPool.Keys.ToHashSet(), request.ParentTemplate.Id);
         foreach (var modSlot in sortedModKeys)
         {
             // Check weapon has slot for mod to fit in
@@ -707,7 +719,7 @@ public class BotEquipmentModGenerator(
     public bool ShouldForceSubStockSlots(string modSlot, EquipmentFilters botEquipConfig, TemplateItem modToAddTemplate)
     {
         // Slots a weapon can store its stock in
-        string[] stockSlots = ["mod_stock", "mod_stock_000", "mod_stock_001", "mod_stock_akms"];
+        HashSet<string> stockSlots = ["mod_stock", "mod_stock_000", "mod_stock_001", "mod_stock_akms"];
 
         // Can the stock hold child items
         var hasSubSlots = modToAddTemplate.Properties.Slots?.Count > 0;
@@ -730,7 +742,7 @@ public class BotEquipmentModGenerator(
             return true;
         }
 
-        return ((string[]) ["mod_sight_front", "mod_sight_rear"]).Contains(modSlot);
+        return _modSightIds.Contains(modSlot);
     }
 
     /// <summary>
@@ -741,17 +753,7 @@ public class BotEquipmentModGenerator(
     /// <returns>true if it can hold a scope</returns>
     public bool ModSlotCanHoldScope(string modSlot, string modsParentId)
     {
-        return ((string[])
+        return _scopeIds.Contains(modSlot.ToLower()) && modsParentId == BaseClasses.MOUNT;
-               [
-                   "mod_scope",
-                   "mod_mount",
-                   "mod_mount_000",
-                   "mod_scope_000",
-                   "mod_scope_001",
-                   "mod_scope_002",
-                   "mod_scope_003"
-               ]).Contains(modSlot.ToLower()) &&
-               modsParentId == BaseClasses.MOUNT;
     }
 
     /// <summary>
@@ -799,7 +801,7 @@ public class BotEquipmentModGenerator(
     /// <param name="unsortedSlotKeys">Array of mod slot strings to sort</param>
     /// <param name="itemTplWithKeysToSort">The Tpl of the item with mod keys being sorted</param>
     /// <returns>Sorted array</returns>
-    public List<string> SortModKeys(List<string> unsortedSlotKeys, string itemTplWithKeysToSort)
+    public HashSet<string> SortModKeys(HashSet<string> unsortedSlotKeys, string itemTplWithKeysToSort)
     {
         // No need to sort with only 1 item in array
         if (unsortedSlotKeys.Count <= 1)
@@ -809,7 +811,7 @@ public class BotEquipmentModGenerator(
 
         var isMount = _itemHelper.IsOfBaseclass(itemTplWithKeysToSort, BaseClasses.MOUNT);
 
-        List<string> sortedKeys = [];
+        HashSet<string> sortedKeys = [];
         var modRecieverKey = "mod_reciever";
         var modMount001Key = "mod_mount_001";
         var modGasBlockKey = "mod_gas_block";
@@ -899,7 +901,7 @@ public class BotEquipmentModGenerator(
             }
         }
 
-        sortedKeys.AddRange(unsortedSlotKeys);
+        sortedKeys.UnionWith(unsortedSlotKeys);
 
         return sortedKeys;
     }
@@ -1138,7 +1140,7 @@ public class BotEquipmentModGenerator(
         }
 
         // Filter mod pool to only items that appear in parents allowed list
-        preFilteredModPool = preFilteredModPool.Where(tpl => parentSlot.Props.Filters[0].Filter.Contains(tpl)).ToList();
+        preFilteredModPool = preFilteredModPool.Where(tpl => parentSlot.Props.Filters[0].Filter.Contains(tpl)).ToHashSet();
         if (preFilteredModPool.Count == 0)
         {
             return new ChooseRandomCompatibleModResult
@@ -1158,10 +1160,10 @@ public class BotEquipmentModGenerator(
     /// <param name="modSpawnType">How should the slot choice be handled - forced/normal etc</param>
     /// <param name="weapon">Weapon mods at current time</param>
     /// <returns>IChooseRandomCompatibleModResult</returns>
-    public ChooseRandomCompatibleModResult GetCompatibleModFromPool(List<string> modPool, ModSpawn? modSpawnType, List<Item> weapon)
+    public ChooseRandomCompatibleModResult GetCompatibleModFromPool(HashSet<string> modPool, ModSpawn? modSpawnType, List<Item> weapon)
     {
         // Create exhaustable pool to pick mod item from
-        var exhaustableModPool = CreateExhaustableArray(modPool.ToList());
+        var exhaustableModPool = CreateExhaustableArray(modPool);
 
         // Create default response if no compatible item is found below
         ChooseRandomCompatibleModResult chosenModResult = new()
@@ -1244,9 +1246,9 @@ public class BotEquipmentModGenerator(
         return chosenModResult;
     }
 
-    public ExhaustableArray<T> CreateExhaustableArray<T>(List<T> itemsToAddToArray)
+    public ExhaustableArray<T> CreateExhaustableArray<T>(ICollection<T> itemsToAddToArray)
     {
-        return new ExhaustableArray<T>(itemsToAddToArray.ToList(), _randomUtil, _cloner);
+        return new ExhaustableArray<T>(itemsToAddToArray, _randomUtil, _cloner);
     }
 
     /// <summary>
@@ -1255,9 +1257,9 @@ public class BotEquipmentModGenerator(
     /// <param name="modPool"></param>
     /// <param name="tplBlacklist">Tpls that are incompatible and should not be used</param>
     /// <returns>string array of compatible mod tpls with weapon</returns>
-    public List<string> GetFilteredModPool(HashSet<string> modPool, HashSet<string> tplBlacklist)
+    public HashSet<string> GetFilteredModPool(HashSet<string> modPool, HashSet<string> tplBlacklist)
     {
-        return modPool.Where(tpl => !tplBlacklist.Contains(tpl)).ToList();
+        return modPool.Where(tpl => !tplBlacklist.Contains(tpl)).ToHashSet();
     }
 
     /// <summary>
@@ -1442,7 +1444,7 @@ public class BotEquipmentModGenerator(
     ///     e.g. mod_magazine / patron_in_weapon_000
     /// </summary>
     /// <returns>string array</returns>
-    public List<string> GetAmmoContainers()
+    public HashSet<string> GetAmmoContainers()
     {
         return ["mod_magazine", "patron_in_weapon", "patron_in_weapon_000", "patron_in_weapon_001", "cartridges"];
     }
@@ -1781,7 +1783,7 @@ public class BotEquipmentModGenerator(
             {
                 // Check to see if mount has a scope slot (only include primary slot, ignore the rest like the backup sight slots)
                 // Should only find 1 as there's currently no items with a mod_scope AND a mod_scope_000
-                List<string> filter = ["mod_scope", "mod_scope_000"];
+                HashSet<string> filter = ["mod_scope", "mod_scope_000"];
                 var scopeSlot = itemDetails.Properties.Slots.Where(
                     slot =>
                         filter.Contains(slot.Name)
@@ -1806,7 +1808,7 @@ public class BotEquipmentModGenerator(
         }
 
         // No mods added to return list after filtering has occurred, send back the original mod list
-        if (filteredScopesAndMods is null || filteredScopesAndMods.Count() == 0)
+        if (filteredScopesAndMods.Count == 0)
         {
             if (_logger.IsLogEnabled(LogLevel.Debug))
             {

Libraries/Core/Generators/BotInventoryGenerator.cs

@@ -40,7 +40,7 @@ public class BotInventoryGenerator(
     private readonly BotConfig _botConfig = _configServer.GetConfig<BotConfig>();
 
     // Slots handled individually inside `GenerateAndAddEquipmentToBot`
-    private readonly List<EquipmentSlots> _excludedEquipmentSlots =
+    private readonly HashSet<EquipmentSlots> _excludedEquipmentSlots =
     [
         EquipmentSlots.Pockets,
         EquipmentSlots.FirstPrimaryWeapon,
@@ -449,7 +449,7 @@ public class BotInventoryGenerator(
     /// <returns>true when item added</returns>
     public bool GenerateEquipment(GenerateEquipmentProperties settings)
     {
-        List<string> slotsToCheck = [EquipmentSlots.Pockets.ToString(), EquipmentSlots.SecuredContainer.ToString()];
+        HashSet<string> slotsToCheck = [EquipmentSlots.Pockets.ToString(), EquipmentSlots.SecuredContainer.ToString()];
         double? spawnChance = slotsToCheck.Contains(settings.RootEquipmentSlot.ToString())
             ? 100
             : settings.SpawnChances.EquipmentChances.GetValueOrDefault(settings.RootEquipmentSlot.ToString());
@@ -589,7 +589,7 @@ public class BotInventoryGenerator(
     /// <param name="itemTpl">Item mod pool is being retrieved and filtered</param>
     /// <param name="equipmentBlacklist">Blacklist to filter mod pool with</param>
     /// <returns>Filtered pool of mods</returns>
-    public Dictionary<string, HashSet<string>> GetFilteredDynamicModsForItem(string itemTpl, Dictionary<string, List<string>> equipmentBlacklist)
+    public Dictionary<string, HashSet<string>> GetFilteredDynamicModsForItem(string itemTpl, Dictionary<string, HashSet<string>> equipmentBlacklist)
     {
         var modPool = _botEquipmentModPoolService.GetModsForGearSlot(itemTpl);
         foreach (var modSlot in modPool)

Libraries/Core/Generators/BotLootGenerator.cs

@@ -368,9 +368,9 @@ public class BotLootGenerator(
     /// </summary>
     /// <param name="botInventory"></param>
     /// <returns></returns>
-    private List<EquipmentSlots> GetAvailableContainersBotCanStoreItemsIn(BotBaseInventory botInventory)
+    private HashSet<EquipmentSlots> GetAvailableContainersBotCanStoreItemsIn(BotBaseInventory botInventory)
     {
-        List<EquipmentSlots> result = [EquipmentSlots.Pockets];
+        HashSet<EquipmentSlots> result = [EquipmentSlots.Pockets];
 
         if ((botInventory.Items ?? []).Any(item => item.SlotId == EquipmentSlots.TacticalVest.ToString()))
         {
@@ -438,7 +438,7 @@ public class BotLootGenerator(
     private void AddLootFromPool
     (
         Dictionary<string, double> pool,
-        List<EquipmentSlots> equipmentSlots,
+        HashSet<EquipmentSlots> equipmentSlots,
         double totalItemCount,
         BotBaseInventory inventoryToAddItemsTo,
         string botRole,

Libraries/Core/Generators/BotWeaponGenerator.cs

@@ -200,9 +200,8 @@ public class BotWeaponGenerator(
         }
 
         // Add cartridge(s) to gun chamber(s)
-        if (weaponItemTemplate.Properties.Chambers?.Any() ??
+        if (weaponItemTemplate.Properties?.Chambers?.Count > 0 &&
-            (false &&
+             weaponItemTemplate.Properties.Chambers[0].Props.Filters[0].Filter.Contains(ammoTpl))
-             weaponItemTemplate.Properties.Chambers[0].Props.Filters[0].Filter.Contains(ammoTpl)))
         {
             // Guns have variety of possible Chamber ids, patron_in_weapon/patron_in_weapon_000/patron_in_weapon_001
             var chamberSlotNames = weaponItemTemplate.Properties.Chambers.Select(chamberSlot => chamberSlot.Name);
@@ -500,7 +499,7 @@ public class BotWeaponGenerator(
         {
             var id = _hashUtil.Generate();
             _botGeneratorHelper.AddItemWithChildrenToEquipmentSlot(
-                new List<EquipmentSlots>
+                new HashSet<EquipmentSlots>
                 {
                     EquipmentSlots.SecuredContainer
                 },
@@ -634,7 +633,7 @@ public class BotWeaponGenerator(
     /// </summary>
     /// <param name="weaponTemplate">Weapon db template to get cartridges for</param>
     /// <returns>List of cartridge tpls</returns>
-    protected List<string>? GetCompatibleCartridgesFromWeaponTemplate(TemplateItem weaponTemplate)
+    protected HashSet<string>? GetCompatibleCartridgesFromWeaponTemplate(TemplateItem weaponTemplate)
     {
         var cartridges = weaponTemplate.Properties?.Chambers.FirstOrDefault()?.Props?.Filters?[0].Filter;
         if (cartridges is not null)
@@ -645,7 +644,7 @@ public class BotWeaponGenerator(
         // Fallback to the magazine if possible, e.g. for revolvers
         //  Grab the magazines template
         var firstMagazine = weaponTemplate.Properties.Slots.FirstOrDefault(slot => slot.Name == "mod_magazine");
-        var magazineTemplate = _itemHelper.GetItem(firstMagazine.Props.Filters?[0].Filter[0]);
+        var magazineTemplate = _itemHelper.GetItem(firstMagazine.Props.Filters?[0].Filter.FirstOrDefault());
         var magProperties = magazineTemplate.Value.Properties;
 
         // Get the first slots array of cartridges
@@ -683,14 +682,11 @@ public class BotWeaponGenerator(
         if (weaponTemplate.Properties.LinkedWeapon is not null)
         {
             var ammoInChamber = _itemHelper.GetItem(
-                weaponTemplate.Properties.Chambers[0].Props.Filters[0].Filter[0]
+                weaponTemplate.Properties.Chambers[0].Props.Filters[0].Filter.FirstOrDefault()
             );
-            if (!ammoInChamber.Key)
+            return !ammoInChamber.Key
-            {
+                ? null
-                return null;
+                : ammoInChamber.Value.Properties.Caliber;
-            }
-
-            return ammoInChamber.Value.Properties.Caliber;
         }
 
         return null;

Libraries/Core/Generators/FenceBaseAssortGenerator.cs

@@ -227,7 +227,7 @@ public class FenceBaseAssortGenerator(
         if (itemHelper.IsOfBaseclass(rootItemDb.Id, BaseClasses.AMMO_BOX))
         {
             // Get the cartridge tpl found inside ammo box
-            var cartridgeTplInBox = rootItemDb.Properties.StackSlots[0].Props.Filters[0].Filter[0];
+            var cartridgeTplInBox = rootItemDb.Properties.StackSlots[0].Props.Filters[0].Filter.FirstOrDefault();
 
             // Look up cartridge tpl in db
             var ammoItemDb = itemHelper.GetItem(cartridgeTplInBox);

Libraries/Core/Generators/LocationLootGenerator.cs

@@ -823,7 +823,7 @@ public class LocationLootGenerator(
             }
 
             // Get an array of allowed IDs after above filtering has occured
-            var validItemIds = spawnPoint.Template.Items.Select(item => item.Id).ToList();
+            var validItemIds = spawnPoint.Template.Items.Select(item => item.Id).ToHashSet();
 
             // Construct container to hold above filtered items, letting us pick an item for the spot
             var itemArray = new ProbabilityObjectArray<string, double?>(_mathUtil, _cloner);

Libraries/Core/Generators/LootGenerator.cs

@@ -219,7 +219,7 @@ public class LootGenerator(
     /// <param name="blockSeasonalItemsOutOfSeason">Prevent seasonal items appearing outside their defined season</param>
     /// <returns>results of filtering + blacklist used</returns>
     protected ItemRewardPoolResults GetItemRewardPool(
-        List<string> itemTplBlacklist,
+        HashSet<string> itemTplBlacklist,
         List<string> itemTypeWhitelist,
         bool useRewardItemBlacklist,
         bool allowBossItems,

Libraries/Core/Generators/PlayerScavGenerator.cs

@@ -139,7 +139,7 @@ public class PlayerScavGenerator(
     /// <param name="scavData"></param>
     /// <param name="containersToAddTo">Possible slotIds to add loot to</param>
     protected void AddAdditionalLootToPlayerScavContainers(Dictionary<string, double> possibleItemsToAdd, BotBase scavData,
-        List<EquipmentSlots> containersToAddTo)
+        HashSet<EquipmentSlots> containersToAddTo)
     {
         foreach (var tpl in possibleItemsToAdd)
         {

Libraries/Core/Generators/RagfairAssortGenerator.cs

@@ -71,7 +71,7 @@ public class RagfairAssortGenerator(
         var dbItemsClone = itemHelper.GetItems().Where(item => item.Type != "Node");
 
         /** Store processed preset tpls so we dont add them when procesing non-preset items */
-        List<string> processedArmorItems = [];
+        HashSet<string> processedArmorItems = [];
         var seasonalEventActive = seasonalEventService.SeasonalEventEnabled();
         var seasonalItemTplBlacklist = seasonalEventService.GetInactiveSeasonalEventItems();
 

Libraries/Core/Generators/RagfairOfferGenerator.cs

@@ -529,7 +529,7 @@ public class RagfairOfferGenerator(
 
                 // Latest first, to ensure we don't move later items off by 1 each time we remove an item below it
                 var indexesToRemove = offerItemPlatesToRemove.Select(plateItem => itemWithChildren.IndexOf(plateItem))
-                    .ToList();
+                    .ToHashSet();
                 foreach (var index in indexesToRemove.OrderByDescending(x => x))
                 {
                     itemWithChildren.RemoveAt(index);

Libraries/Core/Generators/RepeatableQuestGenerator.cs

@@ -556,7 +556,7 @@ public class RepeatableQuestGenerator(
             var itemIdsWhitelisted = itemWhitelist
                 .Where(p => p.MinPlayerLevel <= pmcLevel)
                 .SelectMany(x => x.ItemIds)
-                .ToList(); //.Aggregate((a, p) => a.Concat(p.ItemIds), []);
+                .ToHashSet(); //.Aggregate((a, p) => a.Concat(p.ItemIds), []);
             itemSelection = itemSelection.Where(
                     x =>
                     {
@@ -579,7 +579,7 @@ public class RepeatableQuestGenerator(
             var itemIdsBlacklisted = itemBlacklist
                 .Where(p => p.MinPlayerLevel <= pmcLevel)
                 .SelectMany(x => x.ItemIds)
-                .ToList(); //.Aggregate(List<ItemsBlacklist> , (a, p) => a.Concat(p.ItemIds) );
+                .ToHashSet(); //.Aggregate(List<ItemsBlacklist> , (a, p) => a.Concat(p.ItemIds) );
 
             itemSelection = itemSelection.Where(
                     x =>

Libraries/Core/Helpers/BotGeneratorHelper.cs

@@ -331,7 +331,7 @@ public class BotGeneratorHelper(
     public ChooseRandomCompatibleModResult IsItemIncompatibleWithCurrentItems(List<Item> itemsEquipped, string tplToCheck, string equipmentSlot)
     {
         // Skip slots that have no incompatibilities
-        List<string> slotsToCheck = ["Scabbard", "Backpack", "SecureContainer", "Holster", "ArmBand"];
+        HashSet<string> slotsToCheck = ["Scabbard", "Backpack", "SecureContainer", "Holster", "ArmBand"];
         if (slotsToCheck.Contains(equipmentSlot))
         {
             return new ChooseRandomCompatibleModResult
@@ -530,7 +530,7 @@ public class BotGeneratorHelper(
     /// <param name="containersIdFull"></param>
     /// <returns>ItemAddedResult result object</returns>
     public ItemAddedResult AddItemWithChildrenToEquipmentSlot(
-        List<EquipmentSlots> equipmentSlots,
+        HashSet<EquipmentSlots> equipmentSlots,
         string rootItemId,
         string? rootItemTplId,
         List<Item> itemWithChildren,

Libraries/Core/Helpers/BotHelper.cs

@@ -19,7 +19,7 @@ public class BotHelper(
 {
     protected BotConfig _botConfig = _configServer.GetConfig<BotConfig>();
     protected PmcConfig _pmcConfig = _configServer.GetConfig<PmcConfig>();
-    protected List<string?> _pmcNames = ["usec", "bear", "pmc", "pmcbear", "pmcusec"];
+    protected HashSet<string?> _pmcNames = ["usec", "bear", "pmc", "pmcbear", "pmcusec"];
 
     /// <summary>
     ///     Get a template object for the specified botRole from bots.types db
@@ -119,8 +119,8 @@ public class BotHelper(
     /// <returns>True if role is PMC</returns>
     public bool BotRoleIsPmc(string botRole)
     {
-        List<string> ListToCheck = [_pmcConfig.UsecType.ToLower(), _pmcConfig.BearType.ToLower()];
+        HashSet<string> listToCheck = [_pmcConfig.UsecType.ToLower(), _pmcConfig.BearType.ToLower()];
-        return ListToCheck.Contains(
+        return listToCheck.Contains(
             botRole.ToLower()
         );
     }

Libraries/Core/Helpers/BotWeaponGeneratorHelper.cs

@@ -20,7 +20,7 @@ public class BotWeaponGeneratorHelper(
     LocalisationService _localisationService
 )
 {
-    private readonly List<string> _magCheck = ["CylinderMagazine", "SpringDrivenCylinder"];
+    private readonly HashSet<string> _magCheck = ["CylinderMagazine", "SpringDrivenCylinder"];
 
     /// <summary>
     ///     Get a randomized number of bullets for a specific magazine
@@ -35,7 +35,7 @@ public class BotWeaponGeneratorHelper(
         double? chamberBulletCount = 0;
         if (MagazineIsCylinderRelated(parentItem.Name))
         {
-            var firstSlotAmmoTpl = magTemplate.Properties.Cartridges.FirstOrDefault()?.Props.Filters[0].Filter[0];
+            var firstSlotAmmoTpl = magTemplate.Properties.Cartridges.FirstOrDefault()?.Props.Filters[0].Filter.FirstOrDefault();
             var ammoMaxStackSize = _itemHelper.GetItem(firstSlotAmmoTpl).Value?.Properties?.StackMaxSize ?? 1;
             chamberBulletCount = ammoMaxStackSize == 1
                 ? 1 // Rotating grenade launcher
@@ -110,7 +110,7 @@ public class BotWeaponGeneratorHelper(
         string ammoTpl,
         int cartridgeCount,
         BotBaseInventory inventory,
-        List<EquipmentSlots> equipmentSlotsToAddTo
+        HashSet<EquipmentSlots> equipmentSlotsToAddTo
     )
     {
         if (equipmentSlotsToAddTo is null)

Libraries/Core/Helpers/Dialogue/SPTFriend/Commands/HelloMessageHandler.cs

@@ -12,7 +12,7 @@ public class HelloMessageHandler(
     MailSendService _mailSendService,
     RandomUtil _randomUtil) : IChatMessageHandler
 {
-    protected List<string> _listOfMessages = ["hello", "hi", "sup", "yo", "hey", "bonjour"];
+    protected HashSet<string> _listOfGreetings = ["hello", "hi", "sup", "yo", "hey", "bonjour"];
 
 
     public int GetPriority()
@@ -22,7 +22,7 @@ public class HelloMessageHandler(
 
     public bool CanHandle(string message)
     {
-        return _listOfMessages.Contains(message, StringComparer.OrdinalIgnoreCase);
+        return _listOfGreetings.Contains(message, StringComparer.OrdinalIgnoreCase);
     }
 
     public void Process(string sessionId, UserDialogInfo sptFriendUser, PmcData sender)

Libraries/Core/Helpers/HealthHelper.cs

@@ -210,7 +210,7 @@ public class HealthHelper(
     protected void TransferPostRaidLimbEffectsToProfile(Dictionary<string, BodyPartHealth> postRaidBodyParts, PmcData profileData)
     {
         // Iterate over each body part
-        List<string> effectsToIgnore = ["Dehydration", "Exhaustion"];
+        HashSet<string> effectsToIgnore = ["Dehydration", "Exhaustion"];
         foreach (var bodyPartId in postRaidBodyParts)
         {
             // Get effects on body part from profile

Libraries/Core/Helpers/HideoutHelper.cs

@@ -38,7 +38,7 @@ public class HideoutHelper(
     public const string BitcoinProductionId = "5d5c205bd582a50d042a3c0e";
     public const string WaterCollector = "5d5589c1f934db045e6c5492";
     public const int MaxSkillPoint = 5000;
-    protected List<string> _idCheck = [BitcoinFarm, CultistCircleCraftId];
+    protected HashSet<string> _idCheck = [BitcoinFarm, CultistCircleCraftId];
     protected HideoutConfig hideoutConfig = _configServer.GetConfig<HideoutConfig>();
 
     /// <summary>
@@ -1499,7 +1499,7 @@ public class HideoutHelper(
         var wallBonuses = wallAreaDb.Stages.SelectMany(stage => stage.Value.Bonuses);
 
         // Get all bonus Ids that the wall adds
-        List<string> bonusIdsToRemove = [];
+        HashSet<string> bonusIdsToRemove = [];
         foreach (var bonus in wallBonuses)
         {
             bonusIdsToRemove.Add(bonus.Id);

Libraries/Core/Helpers/InventoryHelper.cs

@@ -39,7 +39,7 @@ public class InventoryHelper(
 )
 {
     // Item types to ignore inside `GetSizeByInventoryItemHash`
-    private readonly List<string> _itemBaseTypesToIgnore = [BaseClasses.BACKPACK, BaseClasses.SEARCHABLE_ITEM, BaseClasses.SIMPLE_CONTAINER];
+    private readonly HashSet<string> _itemBaseTypesToIgnore = [BaseClasses.BACKPACK, BaseClasses.SEARCHABLE_ITEM, BaseClasses.SIMPLE_CONTAINER];
     protected InventoryConfig _inventoryConfig = _configServer.GetConfig<InventoryConfig>();
 
     /// <summary>
@@ -1235,7 +1235,7 @@ public class InventoryHelper(
         }
 
         // Reset fast panel value if item was moved to a container other than pocket/rig (cant be used from fastpanel)
-        List<string> slots = ["pockets", "tacticalvest"];
+        HashSet<string> slots = ["pockets", "tacticalvest"];
         var wasMovedToFastPanelAccessibleContainer = slots.Contains(
             itemParent?.SlotId?.ToLower() ?? ""
         );

Libraries/Core/Helpers/ItemHelper.cs

@@ -16,7 +16,6 @@ namespace Core.Helpers;
 public class ItemHelper(
     ISptLogger<ItemHelper> _logger,
     HashUtil _hashUtil,
-    JsonUtil _jsonUtil,
     RandomUtil _randomUtil,
     MathUtil _mathUtil,
     DatabaseService _databaseService,
@@ -28,7 +27,7 @@ public class ItemHelper(
     ICloner _cloner
 )
 {
-    protected List<string> _defaultInvalidBaseTypes =
+    protected HashSet<string> _defaultInvalidBaseTypes =
     [
         BaseClasses.LOOT_CONTAINER,
         BaseClasses.MOB_CONTAINER,
@@ -39,7 +38,7 @@ public class ItemHelper(
         BaseClasses.POCKETS
     ];
 
-    protected List<string> _slotsAsStrings =
+    protected HashSet<string> _slotsAsStrings =
     [
         EquipmentSlots.Headwear.ToString(),
         EquipmentSlots.Earpiece.ToString(),
@@ -57,6 +56,38 @@ public class ItemHelper(
         EquipmentSlots.Scabbard.ToString()
     ];
 
+    protected HashSet<string> _dogTagTpls =
+    [
+        ItemTpl.BARTER_DOGTAG_BEAR,
+        ItemTpl.BARTER_DOGTAG_BEAR_EOD,
+        ItemTpl.BARTER_DOGTAG_BEAR_TUE,
+        ItemTpl.BARTER_DOGTAG_USEC,
+        ItemTpl.BARTER_DOGTAG_USEC_EOD,
+        ItemTpl.BARTER_DOGTAG_USEC_TUE,
+        ItemTpl.BARTER_DOGTAG_BEAR_PRESTIGE_1,
+        ItemTpl.BARTER_DOGTAG_BEAR_PRESTIGE_2,
+        ItemTpl.BARTER_DOGTAG_USEC_PRESTIGE_1,
+        ItemTpl.BARTER_DOGTAG_USEC_PRESTIGE_2
+    ];
+
+    protected HashSet<string> _softInsertIds =
+    [
+        "groin",
+        "groin_back",
+        "soft_armor_back",
+        "soft_armor_front",
+        "soft_armor_left",
+        "soft_armor_right",
+        "shoulder_l",
+        "shoulder_r",
+        "collar",
+        "helmet_top",
+        "helmet_back",
+        "helmet_eyes",
+        "helmet_jaw",
+        "helmet_ears"
+    ];
+
     /**
      * Does the provided pool of items contain the desired item
      * @param itemPool Item collection to check
@@ -308,7 +339,7 @@ public class ItemHelper(
      * @param tpl the template id / tpl
      * @returns boolean; true for items that may be in player possession and not quest items
      */
-    public bool IsValidItem(string tpl, List<string> invalidBaseTypes = null)
+    public bool IsValidItem(string tpl, ICollection<string>? invalidBaseTypes = null)
     {
         var baseTypes = invalidBaseTypes ?? _defaultInvalidBaseTypes;
         var itemDetails = GetItem(tpl);
@@ -403,8 +434,7 @@ public class ItemHelper(
         }
 
         // Check if item has slots that match soft insert name ids
-        var softInsertIds = GetSoftInsertSlotIds();
+        if (itemDbDetails.Value.Properties.Slots.Any(slot => IsSoftInsertId(slot.Name.ToLower())))
-        if (itemDbDetails.Value.Properties.Slots.Any(slot => softInsertIds.Contains(slot.Name.ToLower())))
         {
             return true;
         }
@@ -414,32 +444,26 @@ public class ItemHelper(
 
     // Get all soft insert slot ids
     // @returns A List of soft insert ids (e.g. soft_armor_back, helmet_top)
-    public List<string> GetSoftInsertSlotIds()
+    public HashSet<string> GetSoftInsertSlotIds()
     {
-        return
+        return _softInsertIds;
-        [
+    }
-            "groin",
+
-            "groin_back",
+    /// <summary>
-            "soft_armor_back",
+    /// Does the passed in slot id match a soft insert id
-            "soft_armor_front",
+    /// </summary>
-            "soft_armor_left",
+    /// <param name="slotId">Id to check</param>
-            "soft_armor_right",
+    /// <returns></returns>
-            "shoulder_l",
+    public bool IsSoftInsertId(string slotId)
-            "shoulder_r",
+    {
-            "collar",
+        return _softInsertIds.Contains(slotId);
-            "helmet_top",
-            "helmet_back",
-            "helmet_eyes",
-            "helmet_jaw",
-            "helmet_ears"
-        ];
     }
 
     // Returns the items total price based on the handbook or as a fallback from the prices.json if the item is not
     // found in the handbook. If the price can't be found at all return 0
     // @param List<string> tpls item tpls to look up the price of
     // @returns Total price in roubles
-    public double GetItemAndChildrenPrice(List<string> tpls)
+    public double GetItemAndChildrenPrice(IEnumerable<string> tpls)
     {
         // Run getItemPrice for each tpl in tpls array, return sum
         return tpls.Aggregate(0, (total, tpl) => total + (int) GetItemPrice(tpl).GetValueOrDefault(0));
@@ -817,21 +841,7 @@ public class ItemHelper(
     /// <returns>True if it is a dogtag.</returns>
     public bool IsDogtag(string tpl)
     {
-        List<string> dogTagTpls =
+        return _dogTagTpls.Contains(tpl);
-        [
-            ItemTpl.BARTER_DOGTAG_BEAR,
-            ItemTpl.BARTER_DOGTAG_BEAR_EOD,
-            ItemTpl.BARTER_DOGTAG_BEAR_TUE,
-            ItemTpl.BARTER_DOGTAG_USEC,
-            ItemTpl.BARTER_DOGTAG_USEC_EOD,
-            ItemTpl.BARTER_DOGTAG_USEC_TUE,
-            ItemTpl.BARTER_DOGTAG_BEAR_PRESTIGE_1,
-            ItemTpl.BARTER_DOGTAG_BEAR_PRESTIGE_2,
-            ItemTpl.BARTER_DOGTAG_USEC_PRESTIGE_1,
-            ItemTpl.BARTER_DOGTAG_USEC_PRESTIGE_2
-        ];
-
-        return dogTagTpls.Contains(tpl);
     }
 
     /// <summary>
@@ -1332,7 +1342,7 @@ public class ItemHelper(
      */
     public bool IsAttachmentAttached(Item item)
     {
-        List<string> check = ["hideout", "main"];
+        HashSet<string> check = ["hideout", "main"];
 
         return !(check.Contains(item.SlotId) || _slotsAsStrings.Contains(item.SlotId) || !int.TryParse(item.SlotId, out _));
     }
@@ -1445,7 +1455,7 @@ public class ItemHelper(
     public void AddCartridgesToAmmoBox(List<Item> ammoBox, TemplateItem ammoBoxDetails)
     {
         var ammoBoxMaxCartridgeCount = ammoBoxDetails.Properties.StackSlots[0].MaxCount;
-        var cartridgeTpl = ammoBoxDetails.Properties.StackSlots[0].Props.Filters[0].Filter[0];
+        var cartridgeTpl = ammoBoxDetails.Properties.StackSlots[0].Props.Filters[0].Filter.FirstOrDefault();
         var cartridgeDetails = GetItem(cartridgeTpl);
         var cartridgeMaxStackSize = cartridgeDetails.Value.Properties.StackMaxSize;
 
@@ -1496,7 +1506,7 @@ public class ItemHelper(
     public void AddSingleStackCartridgesToAmmoBox(List<Item> ammoBox, TemplateItem ammoBoxDetails)
     {
         var ammoBoxMaxCartridgeCount = ammoBoxDetails.Properties?.StackSlots?[0].MaxCount ?? 0;
-        var cartridgeTpl = ammoBoxDetails.Properties?.StackSlots?[0].Props?.Filters?[0].Filter?[0];
+        var cartridgeTpl = ammoBoxDetails.Properties?.StackSlots?[0].Props?.Filters?[0].Filter?.FirstOrDefault();
         ammoBox.Add(
             CreateCartridges(
                 ammoBox[0].Id,
@@ -1684,7 +1694,7 @@ public class ItemHelper(
     protected string? GetRandomValidCaliber(TemplateItem magTemplate)
     {
         var ammoTpls = magTemplate.Properties.Cartridges[0].Props.Filters[0].Filter;
-        List<string> calibers = ammoTpls
+        var calibers = ammoTpls
             .Where(x => GetItem(x).Key)
             .Select(x => GetItem(x).Value.Properties.Caliber)
             .ToList();
@@ -1704,7 +1714,7 @@ public class ItemHelper(
         string caliber,
         Dictionary<string, List<StaticAmmoDetails>> staticAmmoDist,
         string? fallbackCartridgeTpl = null,
-        List<string>? cartridgeWhitelist = null
+        ICollection<string>? cartridgeWhitelist = null
     )
     {
         var ammos = staticAmmoDist.GetValueOrDefault(caliber, []);
@@ -1832,7 +1842,7 @@ public class ItemHelper(
     )
     {
         var result = itemToAdd;
-        HashSet<string> incompatibleModTpls = new();
+        HashSet<string> incompatibleModTpls = [];
         foreach (var slot in itemToAddTemplate.Properties.Slots)
         {
             // If only required mods is requested, skip non-essential
@@ -1856,7 +1866,7 @@ public class ItemHelper(
             }
 
             var itemPool = slot.Props.Filters[0].Filter ?? [];
-            if (itemPool.Count() == 0)
+            if (itemPool.Count == 0)
             {
                 if (_logger.IsLogEnabled(LogLevel.Debug))
                 {
@@ -1896,7 +1906,8 @@ public class ItemHelper(
             var modItemDbDetails = GetItem(modItemToAdd.Template).Value;
 
             // Include conflicting items of newly added mod in pool to be used for next mod choice
-            modItemDbDetails.Properties.ConflictingItems.ForEach(item => incompatibleModTpls.Add(item));
+            incompatibleModTpls.UnionWith(modItemDbDetails.Properties.ConflictingItems);
+
         }
 
         return result;
@@ -1908,7 +1919,7 @@ public class ItemHelper(
     /// <param name="possibleTpls">Tpls to randomly choose from</param>
     /// <param name="incompatibleModTpls">Incompatible tpls to not allow</param>
     /// <returns>Chosen tpl or undefined</returns>
-    public string GetCompatibleTplFromArray(List<string> possibleTpls, HashSet<string> incompatibleModTpls)
+    public string? GetCompatibleTplFromArray(HashSet<string> possibleTpls, HashSet<string> incompatibleModTpls)
     {
         if (!possibleTpls.Any())
         {
@@ -1951,7 +1962,7 @@ public class ItemHelper(
 
     // Get a list of slot names that hold removable plates
     // Returns Array of slot ids (e.g. front_plate)
-    public List<string> GetRemovablePlateSlotIds()
+    public HashSet<string> GetRemovablePlateSlotIds()
     {
         return ["front_plate", "back_plate", "left_side_plate", "right_side_plate"];
     }

Libraries/Core/Helpers/PresetHelper.cs

@@ -189,6 +189,6 @@ public class PresetHelper(
         var tpls = defaultPreset is not null ? defaultPreset.Items.Select(item => item.Template) : [tpl];
 
         // Get price of tpls
-        return _itemHelper.GetItemAndChildrenPrice(tpls.ToList());
+        return _itemHelper.GetItemAndChildrenPrice(tpls);
     }
 }

Libraries/Core/Helpers/ProfileHelper.cs

@@ -199,7 +199,7 @@ public class ProfileHelper(
             Version = _watermark.GetVersionTag(true),
             Mods = new List<ModDetails>(),
             ReceivedGifts = new List<ReceivedGift>(),
-            BlacklistedItemTemplates = new List<string>(),
+            BlacklistedItemTemplates = new HashSet<string>(),
             FreeRepeatableRefreshUsedCount = new Dictionary<string, int>(),
             Migrations = new Dictionary<string, long>(),
             CultistRewards = new Dictionary<string, AcceptedCultistReward>(),

Libraries/Core/Helpers/QuestHelper.cs

@@ -38,7 +38,7 @@ public class QuestHelper(
     ICloner _cloner
 )
 {
-    protected List<QuestStatusEnum> _newlyQuestCheck = [QuestStatusEnum.Started, QuestStatusEnum.AvailableForFinish];
+    protected HashSet<QuestStatusEnum> _newlyQuestCheck = [QuestStatusEnum.Started, QuestStatusEnum.AvailableForFinish];
     protected QuestConfig _questConfig = _configServer.GetConfig<QuestConfig>();
 
     /// <summary>
@@ -413,7 +413,7 @@ public class QuestHelper(
                 }
             );
 
-        return GetQuestsWithOnlyLevelRequirementStartCondition(eligibleQuests.ToList());
+        return GetQuestsWithOnlyLevelRequirementStartCondition(eligibleQuests);
     }
 
     /**
@@ -674,7 +674,7 @@ public class QuestHelper(
      * @param quests quests to process
      * @returns quest list without conditions
      */
-    protected List<Quest> GetQuestsWithOnlyLevelRequirementStartCondition(List<Quest> quests)
+    protected List<Quest> GetQuestsWithOnlyLevelRequirementStartCondition(IEnumerable<Quest> quests)
     {
         return quests.Select(GetQuestWithOnlyLevelRequirementStartCondition).ToList();
     }

Libraries/Core/Helpers/RagfairOfferHelper.cs

@@ -477,7 +477,7 @@ public class RagfairOfferHelper(
     /// <returns>true if quest locked</returns>
     public bool TraderOfferItemQuestLocked(RagfairOffer offer, Dictionary<string, TraderAssort> traderAssorts)
     {
-        var itemIds = offer.Items.Select(x => x.Id).ToList();
+        var itemIds = offer.Items.Select(x => x.Id).ToHashSet();
         //foreach (var item in offer.Items)
         //{
         //    traderAssorts.TryGetValue(offer.User.Id, out var assorts);
@@ -574,9 +574,9 @@ public class RagfairOfferHelper(
         return false;
     }
 
-    protected List<string> GetLoyaltyLockedOffers(List<RagfairOffer> offers, PmcData pmcProfile)
+    protected HashSet<string> GetLoyaltyLockedOffers(List<RagfairOffer> offers, PmcData pmcProfile)
     {
-        var loyaltyLockedOffers = new List<string>();
+        var loyaltyLockedOffers = new HashSet<string>();
         foreach (var offer in offers.Where(offer => OfferIsFromTrader(offer)))
         {
             if (pmcProfile.TradersInfo.TryGetValue(offer.User.Id, out var traderDetails) &&

Libraries/Core/Helpers/TraderAssortHelper.cs

@@ -131,7 +131,7 @@ public class TraderAssortHelper(
     /// </summary>
     /// <param name="assortToFilter">Trader assort to modify</param>
     /// <param name="itemsTplsToRemove">Item TPLs the assort should not have</param>
-    protected void RemoveItemsFromAssort(TraderAssort assortToFilter, List<string> itemsTplsToRemove)
+    protected void RemoveItemsFromAssort(TraderAssort assortToFilter, HashSet<string> itemsTplsToRemove)
     {
         assortToFilter.Items = assortToFilter.Items.Where(
                 item =>

Libraries/Core/Models/Eft/Common/Tables/BotBase.cs

@@ -301,7 +301,7 @@ public record TaskConditionCounter
 public record UnlockedInfo
 {
     [JsonPropertyName("unlockedProductionRecipe")]
-    public List<string>? UnlockedProductionRecipe
+    public HashSet<string>? UnlockedProductionRecipe
     {
         get;
         set;

Libraries/Core/Models/Eft/Common/Tables/Reward.cs

@@ -97,7 +97,7 @@ public record Reward
      * Game editions whitelisted to get reward
      */
     [JsonPropertyName("availableInGameEditions")]
-    public List<string>? AvailableInGameEditions
+    public HashSet<string>? AvailableInGameEditions
     {
         get;
         set;
@@ -107,7 +107,7 @@ public record Reward
      * Game editions blacklisted from getting reward
      */
     [JsonPropertyName("notAvailableInGameEditions")]
-    public List<string>? NotAvailableInGameEditions
+    public HashSet<string>? NotAvailableInGameEditions
     {
         get;
         set;

Libraries/Core/Models/Eft/Common/Tables/TemplateItem.cs

@@ -482,7 +482,7 @@ public record Props
     }
 
     [JsonPropertyName("ConflictingItems")]
-    public List<string>? ConflictingItems
+    public HashSet<string>? ConflictingItems
     {
         get;
         set;
@@ -1509,7 +1509,7 @@ public record Props
     }
 
     [JsonPropertyName("weapFireType")]
-    public List<string>? WeapFireType
+    public HashSet<string>? WeapFireType
     {
         get;
         set;
@@ -3604,7 +3604,7 @@ public record GridProps
 public record GridFilter
 {
     [JsonPropertyName("Filter")]
-    public List<string>? Filter
+    public HashSet<string>? Filter
     {
         get;
         set;
@@ -3755,7 +3755,7 @@ public record SlotFilter
     }
 
     [JsonPropertyName("Filter")]
-    public List<string>? Filter
+    public HashSet<string>? Filter
     {
         get;
         set;

Libraries/Core/Models/Eft/Profile/SptProfile.cs

@@ -733,7 +733,7 @@ public record Spt
      * item TPLs blacklisted from being sold on flea for this profile
      */
     [JsonPropertyName("blacklistedItemTpls")]
-    public List<string>? BlacklistedItemTemplates
+    public HashSet<string>? BlacklistedItemTemplates
     {
         get;
         set;

Libraries/Core/Models/Enums/Money.cs

@@ -7,7 +7,7 @@ public record Money
     public const string DOLLARS = "5696686a4bdc2da3298b456a";
     public const string GP = "5d235b4d86f7742e017bc88a";
 
-    public static List<string> GetMoneyTpls()
+    public static HashSet<string> GetMoneyTpls()
     {
         return [ROUBLES, EUROS, DOLLARS, GP];
     }

Libraries/Core/Models/Spt/Bots/GenerateEquipmentProperties.cs

@@ -82,7 +82,7 @@ public record GenerateEquipmentProperties
     ///     OPTIONAL - Do not generate mods for tpls in this array
     /// </summary>
     [JsonPropertyName("generateModsBlacklist")]
-    public List<string>? GenerateModsBlacklist
+    public HashSet<string>? GenerateModsBlacklist
     {
         get;
         set;

Libraries/Core/Models/Spt/Config/BotConfig.cs

@@ -160,7 +160,7 @@ public record BotConfig : BaseConfig
      * Bot roles in this array will be given a dog tag on generation
      */
     [JsonPropertyName("botRolesWithDogTags")]
-    public List<string> BotRolesWithDogTags
+    public HashSet<string> BotRolesWithDogTags
     {
         get;
         set;
@@ -190,7 +190,7 @@ public record BotConfig : BaseConfig
      * Tpls for low profile gas blocks
      */
     [JsonPropertyName("lowProfileGasBlockTpls")]
-    public List<string> LowProfileGasBlockTpls
+    public HashSet<string> LowProfileGasBlockTpls
     {
         get;
         set;
@@ -200,7 +200,7 @@ public record BotConfig : BaseConfig
      * What bottypes should be excluded from having loot generated on them (backpack/pocket/vest) does not disable food/drink/special/
      */
     [JsonPropertyName("disableLootOnBotTypes")]
-    public List<string> DisableLootOnBotTypes
+    public HashSet<string> DisableLootOnBotTypes
     {
         get;
         set;
@@ -220,7 +220,7 @@ public record BotConfig : BaseConfig
      * Bot roles that must have a unique name when generated vs other bots in raid
      */
     [JsonPropertyName("botRolesThatMustHaveUniqueName")]
-    public List<string> BotRolesThatMustHaveUniqueName
+    public HashSet<string> BotRolesThatMustHaveUniqueName
     {
         get;
         set;
@@ -702,7 +702,7 @@ public record EquipmentFilters
     ///     What additional slot ids should be seen as required when choosing a mod to add to a weapon
     /// </summary>
     [JsonPropertyName("weaponSlotIdsToMakeRequired")]
-    public List<string>? WeaponSlotIdsToMakeRequired
+    public HashSet<string>? WeaponSlotIdsToMakeRequired
     {
         get;
         set;
@@ -929,7 +929,7 @@ public record EquipmentFilterDetails
     ///     Key: mod slot name e.g. mod_magazine, value: item tpls
     /// </summary>
     [JsonPropertyName("equipment")]
-    public Dictionary<string, List<string>>? Equipment
+    public Dictionary<string, HashSet<string>>? Equipment
     {
         get;
         set;
@@ -939,7 +939,7 @@ public record EquipmentFilterDetails
     ///     Key: equipment slot name e.g. FirstPrimaryWeapon, value: item tpls
     /// </summary>
     [JsonPropertyName("gear")]
-    public Dictionary<EquipmentSlots, List<string>>? Gear
+    public Dictionary<EquipmentSlots, HashSet<string>>? Gear
     {
         get;
         set;
@@ -949,7 +949,7 @@ public record EquipmentFilterDetails
     ///     Key: cartridge type e.g. Caliber23x75, value: item tpls
     /// </summary>
     [JsonPropertyName("cartridge")]
-    public Dictionary<string, List<string>>? Cartridge
+    public Dictionary<string, HashSet<string>>? Cartridge
     {
         get;
         set;

Libraries/Core/Models/Spt/Config/CoreConfig.cs

@@ -335,7 +335,7 @@ public record ServerFeatures
      * Keyed to profile type e.g. "Standard" or "SPT Developer"
      */
     [JsonPropertyName("createNewProfileTypesBlacklist")]
-    public List<string> CreateNewProfileTypesBlacklist
+    public HashSet<string> CreateNewProfileTypesBlacklist
     {
         get;
         set;

Libraries/Core/Models/Spt/Config/InventoryConfig.cs

@@ -60,7 +60,7 @@ public record InventoryConfig : BaseConfig
      * Container Tpls that should be deprioritised when choosing where to take money from for payments
      */
     [JsonPropertyName("deprioritisedMoneyContainers")]
-    public List<string> DeprioritisedMoneyContainers
+    public HashSet<string> DeprioritisedMoneyContainers
     {
         get;
         set;

Libraries/Core/Models/Spt/Config/LocationConfig.cs

@@ -51,7 +51,7 @@ public record LocationConfig : BaseConfig
     ///     Open zones to add to map
     /// </summary>
     [JsonPropertyName("openZones")]
-    public Dictionary<string, List<string>> OpenZones
+    public Dictionary<string, HashSet<string>> OpenZones
     {
         get;
         set;
@@ -61,7 +61,7 @@ public record LocationConfig : BaseConfig
     ///     Key = map id, value = item tpls that should only have one forced loot spawn position
     /// </summary>
     [JsonPropertyName("forcedLootSingleSpawnById")]
-    public Dictionary<string, List<string>> ForcedLootSingleSpawnById
+    public Dictionary<string, HashSet<string>> ForcedLootSingleSpawnById
     {
         get;
         set;
@@ -218,7 +218,7 @@ public record LocationConfig : BaseConfig
     ///     Containers to remove all children from when generating static/loose loot
     /// </summary>
     [JsonPropertyName("tplsToStripChildItemsFrom")]
-    public List<string> TplsToStripChildItemsFrom
+    public HashSet<string> TplsToStripChildItemsFrom
     {
         get;
         set;
@@ -228,7 +228,7 @@ public record LocationConfig : BaseConfig
     ///     Map ids players cannot visit
     /// </summary>
     [JsonPropertyName("nonMaps")]
-    public List<string> NonMaps
+    public HashSet<string> NonMaps
     {
         get;
         set;

Libraries/Core/Models/Spt/Config/PmcConfig.cs

@@ -370,7 +370,7 @@ public record SlotLootSettings
      * Item Type whitelist
      */
     [JsonPropertyName("whitelist")]
-    public List<string> Whitelist
+    public HashSet<string> Whitelist
     {
         get;
         set;
@@ -380,7 +380,7 @@ public record SlotLootSettings
      * Item tpl blacklist
      */
     [JsonPropertyName("blacklist")]
-    public List<string> Blacklist
+    public HashSet<string> Blacklist
     {
         get;
         set;

Libraries/Core/Models/Spt/Config/QuestConfig.cs

@@ -62,14 +62,14 @@ public record QuestConfig : BaseConfig
     }
 
     [JsonPropertyName("bearOnlyQuests")]
-    public List<string>? BearOnlyQuests
+    public HashSet<string>? BearOnlyQuests
     {
         get;
         set;
     }
 
     [JsonPropertyName("usecOnlyQuests")]
-    public List<string>? UsecOnlyQuests
+    public HashSet<string>? UsecOnlyQuests
     {
         get;
         set;
@@ -79,7 +79,7 @@ public record QuestConfig : BaseConfig
      * Quests that the keyed game version do not see/access
      */
     [JsonPropertyName("profileBlacklist")]
-    public Dictionary<string, List<string>>? ProfileBlacklist
+    public Dictionary<string, HashSet<string>>? ProfileBlacklist
     {
         get;
         set;
@@ -89,7 +89,7 @@ public record QuestConfig : BaseConfig
      * key=questid, gameversions that can see/access quest
      */
     [JsonPropertyName("profileWhitelist")]
-    public Dictionary<string, List<string>>? ProfileWhitelist
+    public Dictionary<string, HashSet<string>>? ProfileWhitelist
     {
         get;
         set;
@@ -266,7 +266,7 @@ public record RepeatableQuestConfig
      * Item base types to block when generating rewards
      */
     [JsonPropertyName("rewardBaseTypeBlacklist")]
-    public List<string>? RewardBaseTypeBlacklist
+    public HashSet<string>? RewardBaseTypeBlacklist
     {
         get;
         set;
@@ -276,7 +276,7 @@ public record RepeatableQuestConfig
      * Item tplIds to ignore when generating rewards
      */
     [JsonPropertyName("rewardBlacklist")]
-    public List<string>? RewardBlacklist
+    public HashSet<string>? RewardBlacklist
     {
         get;
         set;

Libraries/Core/Models/Spt/Config/RagfairConfig.cs

@@ -228,7 +228,7 @@ public record Dynamic
 
     [JsonPropertyName("ignoreQualityPriceVarianceBlacklist")]
     /** Tpls that should not use the variable price system when their quality is < 100% (lower dura/uses = lower price) */
-    public List<string> IgnoreQualityPriceVarianceBlacklist
+    public HashSet<string> IgnoreQualityPriceVarianceBlacklist
     {
         get;
         set;
@@ -306,7 +306,7 @@ public record Dynamic
 
     [JsonPropertyName("showAsSingleStack")]
     /** Item tpls that should be forced to sell as a single item */
-    public List<string> ShowAsSingleStack
+    public HashSet<string> ShowAsSingleStack
     {
         get;
         set;
@@ -435,7 +435,7 @@ public record BarterDetails
      * Item Tpls to never be turned into a barter
      */
     [JsonPropertyName("itemTypeBlacklist")]
-    public List<string> ItemTypeBlacklist
+    public HashSet<string> ItemTypeBlacklist
     {
         get;
         set;
@@ -578,7 +578,7 @@ public record RagfairBlacklist
     ///     Custom blacklist for item Tpls
     /// </summary>
     [JsonPropertyName("custom")]
-    public List<string> Custom
+    public HashSet<string> Custom
     {
         get;
         set;
@@ -638,7 +638,7 @@ public record RagfairBlacklist
     ///     Custom category blacklist for parent Ids
     /// </summary>
     [JsonPropertyName("customItemCategoryList")]
-    public List<string> CustomItemCategoryList
+    public HashSet<string> CustomItemCategoryList
     {
         get;
         set;
@@ -661,7 +661,7 @@ public record ArmorPlateBlacklistSettings
     ///     Item slots to NOT remove from items on flea
     /// </summary>
     [JsonPropertyName("ignoreSlots")]
-    public List<string> IgnoreSlots
+    public HashSet<string> IgnoreSlots
     {
         get;
         set;
@@ -724,7 +724,7 @@ public record ArmorSettings
     ///     What slots are to be removed when removeRemovablePlateChance is true
     /// </summary>
     [JsonPropertyName("plateSlotIdToRemovePool")]
-    public List<string> PlateSlotIdToRemovePool
+    public HashSet<string>? PlateSlotIdToRemovePool
     {
         get;
         set;

Libraries/Core/Models/Spt/Config/ScavCaseConfig.cs

@@ -34,14 +34,14 @@ public record ScavCaseConfig : BaseConfig
     }
 
     [JsonPropertyName("rewardItemParentBlacklist")]
-    public List<string> RewardItemParentBlacklist
+    public HashSet<string> RewardItemParentBlacklist
     {
         get;
         set;
     }
 
     [JsonPropertyName("rewardItemBlacklist")]
-    public List<string> RewardItemBlacklist
+    public HashSet<string> RewardItemBlacklist
     {
         get;
         set;

Libraries/Core/Models/Spt/Config/TraderConfig.cs

@@ -250,7 +250,7 @@ public record FenceConfig
     }
 
     [JsonPropertyName("blacklist")]
-    public List<string> Blacklist
+    public HashSet<string> Blacklist
     {
         get;
         set;

Libraries/Core/Models/Spt/Services/LootRequest.cs

@@ -50,7 +50,7 @@ public record LootRequest
     ///     Item tpl blacklist to exclude
     /// </summary>
     [JsonPropertyName("itemBlacklist")]
-    public List<string>? ItemBlacklist
+    public HashSet<string>? ItemBlacklist
     {
         get;
         set;

Libraries/Core/Services/AirdropService.cs

@@ -171,7 +171,7 @@ public class AirdropService(
         var itemsMatchingTypeBlacklist = _itemHelper.GetItems()
             .Where(templateItem => !string.IsNullOrEmpty(templateItem.Parent))
             .Where(templateItem => _itemHelper.IsOfBaseclasses(templateItem.Parent, itemTypeBlacklist))
-            .Select(templateItem => templateItem.Id);
+            .Select(templateItem => templateItem.Id).ToHashSet();
         var itemBlacklist = new HashSet<string>();
         itemBlacklist.UnionWith(lootSettingsByType.ItemBlacklist);
         itemBlacklist.UnionWith(_itemFilterService.GetItemRewardBlacklist());
@@ -185,7 +185,7 @@ public class AirdropService(
             ArmorPresetCount = lootSettingsByType.ArmorPresetCount,
             ItemCount = lootSettingsByType.ItemCount,
             WeaponCrateCount = lootSettingsByType.WeaponCrateCount,
-            ItemBlacklist = itemBlacklist.ToList(),
+            ItemBlacklist = itemBlacklist,
             ItemTypeWhitelist = lootSettingsByType.ItemTypeWhitelist,
             ItemLimits = lootSettingsByType.ItemLimits,
             ItemStackLimits = lootSettingsByType.ItemStackLimits,

Libraries/Core/Services/BotEquipmentFilterService.cs

@@ -322,7 +322,7 @@ public class BotEquipmentFilterService
                 var botAmmo = baseBotNode.BotInventory.Ammo[ammoCaliberKvP.Key];
 
                 // Skip cartridge slot if blacklist doesn't exist / is empty
-                blacklist.Cartridge.TryGetValue(ammoCaliberKvP.Key, out List<string> cartridgeCaliberBlacklist);
+                blacklist.Cartridge.TryGetValue(ammoCaliberKvP.Key, out var cartridgeCaliberBlacklist);
                 if (cartridgeCaliberBlacklist is null || cartridgeCaliberBlacklist.Count == 0)
                 {
                     continue;

Libraries/Core/Services/BotLootCacheService.cs

@@ -468,23 +468,6 @@ public class BotLootCacheService(
         }
     }
 
-    /// <summary>
-    ///     Add unique items into combined pool
-    /// </summary>
-    /// <param name="poolToAddTo">Pool of items to add to</param>
-    /// <param name="itemsToAdd">items to add to combined pool if unique</param>
-    protected void AddUniqueItemsToPool(List<TemplateItem> poolToAddTo, List<TemplateItem> itemsToAdd)
-    {
-        if (poolToAddTo.Count() == 0)
-        {
-            poolToAddTo.AddRange(itemsToAdd);
-            return;
-        }
-
-        poolToAddTo.Concat(itemsToAdd);
-        poolToAddTo = poolToAddTo.Distinct().ToList();
-    }
-
     protected void AddItemsToPool(Dictionary<string, double> poolToAddTo, Dictionary<string, double> poolOfItemsToAdd)
     {
         foreach (var tpl in poolOfItemsToAdd)

Libraries/Core/Services/BotNameService.cs

@@ -44,7 +44,7 @@ public class BotNameService(
         BotType botJsonTemplate,
         BotGenerationDetails botGenerationDetails,
         string botRole,
-        List<string>? uniqueRoles = null)
+        HashSet<string>? uniqueRoles = null)
     {
         var isPmc = botGenerationDetails.IsPmc;
 

Libraries/Core/Services/FenceService.cs

@@ -1376,7 +1376,7 @@ public class FenceService(
     protected void RemoveRandomModsOfItem(List<Item> itemAndMods)
     {
         // Items to be removed from inventory
-        var toDelete = new List<string>();
+        var toDelete = new HashSet<string>();
 
         // Find mods to remove from item that could've been scavenged by other players in-raid
         foreach (var itemMod in itemAndMods)
@@ -1391,7 +1391,7 @@ public class FenceService(
                 }
 
                 // Remove item and its sub-items to prevent orphans
-                toDelete.AddRange(itemHelper.FindAndReturnChildrenByItems(itemAndMods, itemMod.Id));
+                toDelete.UnionWith(itemHelper.FindAndReturnChildrenByItems(itemAndMods, itemMod.Id));
             }
         }
 
@@ -1411,7 +1411,7 @@ public class FenceService(
      * @param itemsBeingDeleted Current list of items on weapon being deleted
      * @returns True if item will be removed
      */
-    protected bool PresetModItemWillBeRemoved(Item weaponMod, List<string> itemsBeingDeleted)
+    protected bool PresetModItemWillBeRemoved(Item weaponMod, HashSet<string> itemsBeingDeleted)
     {
         var slotIdsThatCanFail = traderConfig.Fence.PresetSlotsToRemoveChancePercent;
         if (!slotIdsThatCanFail.TryGetValue(weaponMod.SlotId, out var removalChance) || removalChance == 0.0)

Libraries/Core/Services/ItemFilterService.cs

@@ -27,10 +27,7 @@ public class ItemFilterService(
     {
         if (_itemBlacklistCache.Count == 0)
         {
-            foreach (var item in _itemConfig.Blacklist)
+            _itemBlacklistCache.UnionWith(_itemConfig.Blacklist);
-            {
-                _itemBlacklistCache.Add(item);
-            }
         }
 
         return _itemBlacklistCache.Contains(tpl);
@@ -50,36 +47,36 @@ public class ItemFilterService(
      * Get an array of items that should never be given as a reward to player
      * @returns string array of item tpls
      */
-    public List<string> GetItemRewardBlacklist()
+    public HashSet<string> GetItemRewardBlacklist()
     {
-        return _cloner.Clone(_itemConfig.RewardItemBlacklist).ToList();
+        return _cloner.Clone(_itemConfig.RewardItemBlacklist);
     }
 
     /**
      * Get an array of item types that should never be given as a reward to player
      * @returns string array of item base ids
      */
-    public List<string> GetItemRewardBaseTypeBlacklist()
+    public HashSet<string> GetItemRewardBaseTypeBlacklist()
     {
-        return _cloner.Clone(_itemConfig.RewardItemTypeBlacklist).ToList();
+        return _cloner.Clone(_itemConfig.RewardItemTypeBlacklist);
     }
 
     /**
      * Return every template id blacklisted in config/item.json
      * @returns string array of blacklisted template ids
      */
-    public List<string> GetBlacklistedItems()
+    public HashSet<string> GetBlacklistedItems()
     {
-        return _cloner.Clone(_itemConfig.Blacklist).ToList();
+        return _cloner.Clone(_itemConfig.Blacklist);
     }
 
     /**
      * Return every template id blacklisted in config/item.json/lootableItemBlacklist
      * @returns string array of blacklisted template ids
      */
-    public List<string> GetBlacklistedLootableItems()
+    public HashSet<string> GetBlacklistedLootableItems()
     {
-        return _cloner.Clone(_itemConfig.LootableItemBlacklist).ToList();
+        return _cloner.Clone(_itemConfig.LootableItemBlacklist);
     }
 
     /**
@@ -96,9 +93,9 @@ public class ItemFilterService(
      * Return boss items in config/item.json
      * @returns string array of boss item template ids
      */
-    public List<string> GetBossItems()
+    public HashSet<string> GetBossItems()
     {
-        return _cloner.Clone(_itemConfig.BossItems).ToList();
+        return _cloner.Clone(_itemConfig.BossItems).ToHashSet();
     }
 
     /**

Libraries/Core/Services/LocationLifecycleService.cs

@@ -221,7 +221,7 @@ public class LocationLifecycleService
 
         // Find only scav extracts and overwrite existing exits with them
         var scavExtracts = mapExtracts.Where(extract => extract.Side.ToLower() == "scav").ToList();
-        if (scavExtracts.Count() > 0)
+        if (scavExtracts.Count > 0)
             // Scav extracts found, use them
         {
             locationData.Exits.AddRange(scavExtracts);
@@ -342,12 +342,6 @@ public class LocationLifecycleService
             return locationBaseClone;
         }
 
-        // If new spawn system is enabled, clear the spawn waves to prevent x2 spawns
-        if (locationBaseClone.NewSpawn is true)
-        {
-            locationBaseClone.Waves = [];
-        }
-
         // Only requested base data, not loot
         if (!generateLoot)
         {

Libraries/Core/Services/MailSendService.cs

@@ -28,8 +28,8 @@ public class MailSendService(
 )
 {
     private const string _systemSenderId = "59e7125688a45068a6249071";
-    protected List<MessageType> _messageTypes = [MessageType.NPC_TRADER, MessageType.FLEAMARKET_MESSAGE];
+    protected HashSet<MessageType> _messageTypes = [MessageType.NPC_TRADER, MessageType.FLEAMARKET_MESSAGE];
-    protected List<string> _slotNames = ["hideout", "main"];
+    protected HashSet<string> _slotNames = ["hideout", "main"];
 
     /**
      * Send a message from an NPC (e.g. prapor) to the player with or without items using direct message text, do not look up any locale

Libraries/Core/Services/PmcChatResponseService.cs

@@ -91,7 +91,7 @@ public class PmcChatResponseService(
         }
 
         // If killer wasn't a PMC, skip
-        var pmcTypes = new List<string>
+        var pmcTypes = new HashSet<string>
         {
             "pmcUSEC",
             "pmcBEAR"

Libraries/Core/Services/PostDbLoadService.cs

@@ -126,7 +126,7 @@ public class PostDbLoadService(
     private void RemoveNewBeginningRequirementFromPrestige()
     {
         var prestigeDb = _databaseService.GetTemplates().Prestige;
-        var newBeginningQuestId = new List<string>
+        var newBeginningQuestId = new HashSet<string>
         {
             "6761f28a022f60bb320f3e95",
             "6761ff17cdc36bd66102e9d0"

Libraries/Core/Services/RagfairLinkedItemService.cs

@@ -103,7 +103,7 @@ public class RagfairLinkedItemService(
         if (cylinderMod != null)
         {
             // Get the first cylinder filter tpl
-            var cylinderTpl = cylinderMod.Props?.Filters?[0].Filter?[0];
+            var cylinderTpl = cylinderMod.Props?.Filters?[0].Filter?.FirstOrDefault();
             if (!string.IsNullOrEmpty(cylinderTpl))
             {
                 // Get db data for cylinder tpl, add found slots info (camora_xxx) to linked items on revolver weapon

Libraries/Core/Services/RepairService.cs

@@ -594,7 +594,7 @@ public class RepairService(
 
         // Skill < level 10 + repairing armor
         if (
-            new List<SkillTypes>
+            new HashSet<SkillTypes>
             {
                 SkillTypes.LightVests,
                 SkillTypes.HeavyVests
@@ -606,7 +606,7 @@ public class RepairService(
         }
 
         var skillSettings = globals.Configuration.SkillsSettings.GetAllPropsAsDict();
-        BuffSettings buffSettings = null;
+        BuffSettings? buffSettings = null;
         switch (itemSkillType)
         {
             case SkillTypes.LightVests:

Libraries/Core/Services/SeasonalEventService.cs

@@ -26,7 +26,7 @@ public class SeasonalEventService(
 {
     private bool _christmasEventActive;
 
-    protected IReadOnlyList<string> _christmasEventItems =
+    protected HashSet<string> _christmasEventItems =
     [
         ItemTpl.ARMOR_6B13_M_ASSAULT_ARMOR_CHRISTMAS_EDITION,
         ItemTpl.BACKPACK_SANTAS_BAG,
@@ -57,7 +57,7 @@ public class SeasonalEventService(
     private List<SeasonalEvent> _currentlyActiveEvents = [];
     private bool _halloweenEventActive;
 
-    protected IReadOnlyList<string> _halloweenEventItems =
+    protected HashSet<string> _halloweenEventItems =
     [
         ItemTpl.HEADWEAR_JACKOLANTERN_TACTICAL_PUMPKIN_HELMET,
         ItemTpl.FACECOVER_FACELESS_MASK,
@@ -82,7 +82,7 @@ public class SeasonalEventService(
     ///     Get an array of christmas items found in bots inventories as loot
     /// </summary>
     /// <returns>array</returns>
-    public IEnumerable<string> GetChristmasEventItems()
+    public HashSet<string> GetChristmasEventItems()
     {
         return _christmasEventItems;
     }
@@ -91,7 +91,7 @@ public class SeasonalEventService(
     ///     Get an array of halloween items found in bots inventories as loot
     /// </summary>
     /// <returns>array</returns>
-    public IEnumerable<string> GetHalloweenEventItems()
+    public HashSet<string> GetHalloweenEventItems()
     {
         return _halloweenEventItems;
     }
@@ -131,17 +131,17 @@ public class SeasonalEventService(
     ///     or, if halloween and christmas are inactive, return both sets of items
     /// </summary>
     /// <returns>array of tpl strings</returns>
-    public List<string> GetInactiveSeasonalEventItems()
+    public HashSet<string> GetInactiveSeasonalEventItems()
     {
-        var items = new List<string>();
+        var items = new HashSet<string>();
         if (!ChristmasEventEnabled())
         {
-            items.AddRange(_christmasEventItems);
+            items.UnionWith(_christmasEventItems);
         }
 
         if (!HalloweenEventEnabled())
         {
-            items.AddRange(_halloweenEventItems);
+            items.UnionWith(_halloweenEventItems);
         }
 
         return items;
@@ -350,8 +350,8 @@ public class SeasonalEventService(
     public void RemoveChristmasItemsFromBotInventory(BotTypeInventory botInventory, string botRole)
     {
         var christmasItems = GetChristmasEventItems();
-        List<EquipmentSlots> equipmentSlotsToFilter = [EquipmentSlots.FaceCover, EquipmentSlots.Headwear, EquipmentSlots.Backpack, EquipmentSlots.TacticalVest];
+        HashSet<EquipmentSlots> equipmentSlotsToFilter = [EquipmentSlots.FaceCover, EquipmentSlots.Headwear, EquipmentSlots.Backpack, EquipmentSlots.TacticalVest];
-        List<string> lootContainersToFilter = ["Backpack", "Pockets", "TacticalVest"];
+        HashSet<string> lootContainersToFilter = ["Backpack", "Pockets", "TacticalVest"];
 
         // Remove christmas related equipment
         foreach (var equipmentSlotKey in equipmentSlotsToFilter)
@@ -731,9 +731,9 @@ public class SeasonalEventService(
     /// </summary>
     /// <param name="locationInfections">Dict of locations with their infection percentage</param>
     /// <returns>List of location ids</returns>
-    protected List<string> GetLocationsWithZombies(Dictionary<string, double> locationInfections)
+    protected HashSet<string> GetLocationsWithZombies(Dictionary<string, double> locationInfections)
     {
-        var result = new List<string>();
+        var result = new HashSet<string>();
 
         // Get only the locations with an infection above 0
         var infectionKeys = locationInfections.Where(
@@ -743,7 +743,7 @@ public class SeasonalEventService(
         // Convert the infected location id into its generic location id
         foreach (var location in infectionKeys)
         {
-            result.AddRange(GetLocationFromInfectedLocation(location.Key));
+            result.UnionWith(GetLocationFromInfectedLocation(location.Key));
         }
 
         return result;
@@ -794,7 +794,7 @@ public class SeasonalEventService(
     /// </summary>
     /// <param name="eventType">Seasonal event, e.g. HALLOWEEN/CHRISTMAS</param>
     /// <param name="mapIdWhitelist">OPTIONAL - Maps to add bosses to</param>
-    protected void AddEventBossesToMaps(string eventType, List<string> mapIdWhitelist = null)
+    protected void AddEventBossesToMaps(string eventType, HashSet<string>? mapIdWhitelist = null)
     {
         if (!_seasonalEventConfig.EventBossSpawns.TryGetValue(eventType.ToLower(), out var botsToAddPerMap))
         {
@@ -992,7 +992,7 @@ public class SeasonalEventService(
     protected void EnableDancingTree()
     {
         var maps = _databaseService.GetLocations();
-        List<string> mapsToCheck = ["hideout", "base", "privatearea"];
+        HashSet<string> mapsToCheck = ["hideout", "base", "privatearea"];
         foreach (var mapKvP in maps.GetDictionary())
         {
             // Skip maps that have no tree

Tools/ItemTplGenerator/ItemTplGenerator.cs

@@ -410,14 +410,14 @@ public class ItemTplGenerator(
 
     private string GetAmmoBoxPrefix(TemplateItem item)
     {
-        var ammoItem = item.Properties?.StackSlots?[0]?.Props?.Filters?[0]?.Filter?[0];
+        var ammoItem = item.Properties?.StackSlots?[0]?.Props?.Filters?[0]?.Filter?.FirstOrDefault();
 
         return GetAmmoPrefix(items[ammoItem]);
     }
 
     private string GetMagazinePrefix(TemplateItem item)
     {
-        var ammoItem = item.Properties?.Cartridges?[0]?.Props?.Filters?[0]?.Filter?[0];
+        var ammoItem = item.Properties?.Cartridges?[0]?.Props?.Filters?[0]?.Filter?.FirstOrDefault();
 
         return GetAmmoPrefix(items[ammoItem]);
     }