diff --git a/Libraries/SPTarkov.Server.Core/Extensions/ItemExtensions.cs b/Libraries/SPTarkov.Server.Core/Extensions/ItemExtensions.cs
index d8ae838e..efeb0532 100644
--- a/Libraries/SPTarkov.Server.Core/Extensions/ItemExtensions.cs
+++ b/Libraries/SPTarkov.Server.Core/Extensions/ItemExtensions.cs
@@ -198,12 +198,12 @@ namespace SPTarkov.Server.Core.Extensions
         /// <param name="items">List of items (item + possible children)</param>
         /// <param name="baseItemId">Parent item's id</param>
         /// <returns>list of child item ids</returns>
-        public static List<string> FindAndReturnChildrenByItems(
+        public static List<MongoId> FindAndReturnChildrenByItems(
             this IEnumerable<Item> items,
-            string baseItemId
+            MongoId baseItemId
         )
         {
-            List<string> list = [];
+            List<MongoId> list = [];
 
             foreach (var childItem in items)
             {
@@ -312,7 +312,7 @@ namespace SPTarkov.Server.Core.Extensions
                 if (
                     !result.ContainsKey(childItem.Id)
                     && childItem.ParentId != "hideout"
-                    && childItem.ParentId == baseItemId
+                    && childItem.ParentId == baseItemId.ToString()
                 )
                 {
                     foreach (var item in FindAndReturnChildrenAsItems(items, childItem.Id))
@@ -367,7 +367,7 @@ namespace SPTarkov.Server.Core.Extensions
         /// </summary>
         /// <param name="items">Inventory items to look for secure container in</param>
         /// <returns>List of ids</returns>
-        public static List<string> GetSecureContainerItems(this List<Item> items)
+        public static List<MongoId> GetSecureContainerItems(this List<Item> items)
         {
             var secureContainer = items.First(x => x.SlotId == "SecuredContainer");
 
diff --git a/Libraries/SPTarkov.Server.Core/Generators/RagfairOfferGenerator.cs b/Libraries/SPTarkov.Server.Core/Generators/RagfairOfferGenerator.cs
index cece78b4..59d941da 100644
--- a/Libraries/SPTarkov.Server.Core/Generators/RagfairOfferGenerator.cs
+++ b/Libraries/SPTarkov.Server.Core/Generators/RagfairOfferGenerator.cs
@@ -761,7 +761,7 @@ public class RagfairOfferGenerator(
         if (!(profileHelper.IsPlayer(userID) || ragfairServerHelper.IsTrader(userID)))
         {
             var parentId = GetDynamicConditionIdForTpl(itemDetails.Id);
-            if (string.IsNullOrEmpty(parentId))
+            if (parentId == null)
             // No condition details found, don't proceed with modifying item conditions
             {
                 return;
@@ -770,11 +770,11 @@ public class RagfairOfferGenerator(
             // Roll random chance to randomise item condition
             if (
                 randomUtil.GetChance100(
-                    ragfairConfig.Dynamic.Condition[parentId].ConditionChance * 100
+                    ragfairConfig.Dynamic.Condition[parentId.Value].ConditionChance * 100
                 )
             )
             {
-                RandomiseItemCondition(parentId, itemWithMods, itemDetails);
+                RandomiseItemCondition(parentId.Value, itemWithMods, itemDetails);
             }
         }
     }
@@ -784,7 +784,7 @@ public class RagfairOfferGenerator(
     /// </summary>
     /// <param name="tpl"> Item to look for matching condition object</param>
     /// <returns> Condition ID </returns>
-    protected string? GetDynamicConditionIdForTpl(MongoId tpl)
+    protected MongoId? GetDynamicConditionIdForTpl(MongoId tpl)
     {
         // Get keys from condition config dictionary
         var configConditions = ragfairConfig.Dynamic.Condition.Keys;
@@ -806,7 +806,7 @@ public class RagfairOfferGenerator(
     /// <param name="itemWithMods"> Item to adjust condition details of </param>
     /// <param name="itemDetails"> DB Item details of first item in list </param>
     protected void RandomiseItemCondition(
-        string conditionSettingsId,
+        MongoId conditionSettingsId,
         List<Item> itemWithMods,
         TemplateItem itemDetails
     )
diff --git a/Libraries/SPTarkov.Server.Core/Helpers/ItemHelper.cs b/Libraries/SPTarkov.Server.Core/Helpers/ItemHelper.cs
index bc4c1d45..e5ff2177 100644
--- a/Libraries/SPTarkov.Server.Core/Helpers/ItemHelper.cs
+++ b/Libraries/SPTarkov.Server.Core/Helpers/ItemHelper.cs
@@ -1856,29 +1856,33 @@ public class ItemHelper(
         return GetRemovablePlateSlotIds().Contains(slotName.ToLowerInvariant());
     }
 
-    // Get a list of slot names that hold removable plates
-    // Returns Array of slot ids (e.g. front_plate)
+    /// <summary>
+    /// Get a list of slot names that hold removable plates
+    /// </summary>
+    /// <returns>Array of slot ids (e.g. front_plate)</returns>
     public FrozenSet<string> GetRemovablePlateSlotIds()
     {
         return _removablePlateSlotIds;
     }
 
-    // Generate new unique ids for child items while preserving hierarchy
-    // Base/primary item
-    // Primary item + children of primary item
-    // Returns Item array with updated IDs
+    /// <summary>
+    /// Generate new unique ids for child items while preserving hierarchy
+    /// </summary>
+    /// <param name="rootItem">Base/primary item</param>
+    /// <param name="itemWithChildren">Primary item + children of primary item</param>
+    /// <returns>Item array with updated IDs</returns>
     public List<Item> ReparentItemAndChildren(Item rootItem, List<Item> itemWithChildren)
     {
         var oldRootId = itemWithChildren[0].Id;
-        Dictionary<string, MongoId> idMappings = new();
+        Dictionary<string, MongoId> idMappings = [];
 
-        idMappings[oldRootId] = rootItem.Id;
+        idMappings[oldRootId.ToString()] = rootItem.Id;
 
         foreach (var mod in itemWithChildren)
         {
             if (!idMappings.ContainsKey(mod.Id))
             {
-                idMappings[mod.Id] = new MongoId();
+                idMappings[mod.Id.ToString()] = new MongoId();
             }
 
             // Has parentId + no remapping exists for its parent
@@ -1891,7 +1895,7 @@ public class ItemHelper(
                 idMappings[mod.ParentId] = new MongoId();
             }
 
-            mod.Id = idMappings[mod.Id];
+            mod.Id = idMappings[mod.Id.ToString()];
             if (mod.ParentId != null)
             {
                 mod.ParentId = idMappings[mod.ParentId];
diff --git a/Libraries/SPTarkov.Server.Core/Servers/ConfigServer.cs b/Libraries/SPTarkov.Server.Core/Servers/ConfigServer.cs
index ccf09392..607320b5 100644
--- a/Libraries/SPTarkov.Server.Core/Servers/ConfigServer.cs
+++ b/Libraries/SPTarkov.Server.Core/Servers/ConfigServer.cs
@@ -1,3 +1,4 @@
+using System.Collections.Frozen;
 using SPTarkov.DI.Annotations;
 using SPTarkov.Server.Core.Models.Enums;
 using SPTarkov.Server.Core.Models.Spt.Config;
@@ -10,7 +11,7 @@ namespace SPTarkov.Server.Core.Servers;
 [Injectable(InjectionType.Singleton)]
 public class ConfigServer
 {
-    protected readonly string[] acceptableFileExtensions = ["json", "jsonc"];
+    protected readonly FrozenSet<string> acceptableFileExtensions = ["json", "jsonc"];
     protected readonly FileUtil _fileUtil;
     protected readonly JsonUtil _jsonUtil;
     protected readonly ISptLogger<ConfigServer> _logger;
diff --git a/Libraries/SPTarkov.Server.Core/Services/FenceService.cs b/Libraries/SPTarkov.Server.Core/Services/FenceService.cs
index eda5dbc6..a378037d 100644
--- a/Libraries/SPTarkov.Server.Core/Services/FenceService.cs
+++ b/Libraries/SPTarkov.Server.Core/Services/FenceService.cs
@@ -1472,7 +1472,7 @@ public class FenceService(
     protected void RemoveRandomModsOfItem(List<Item> itemAndMods)
     {
         // Items to be removed from inventory
-        var toDelete = new HashSet<string>();
+        var toDelete = new HashSet<MongoId>();
 
         // Find mods to remove from item that could've been scavenged by other players in-raid
         foreach (var itemMod in itemAndMods)
@@ -1507,7 +1507,7 @@ public class FenceService(
     /// <param name="weaponMod"> Weapon mod being checked </param>
     /// <param name="itemsBeingDeleted"> Current list of items on weapon being deleted </param>
     /// <returns> True if item will be removed </returns>
-    protected bool PresetModItemWillBeRemoved(Item weaponMod, HashSet<string> itemsBeingDeleted)
+    protected bool PresetModItemWillBeRemoved(Item weaponMod, HashSet<MongoId> itemsBeingDeleted)
     {
         var slotIdsThatCanFail = traderConfig.Fence.PresetSlotsToRemoveChancePercent;
         if (
diff --git a/Libraries/SPTarkov.Server.Core/Services/RagfairPriceService.cs b/Libraries/SPTarkov.Server.Core/Services/RagfairPriceService.cs
index 03dbb57c..d0d2108d 100644
--- a/Libraries/SPTarkov.Server.Core/Services/RagfairPriceService.cs
+++ b/Libraries/SPTarkov.Server.Core/Services/RagfairPriceService.cs
@@ -312,7 +312,7 @@ public class RagfairPriceService(
         // Make adjustments for unreasonably priced items.
         foreach (var (key, value) in _ragfairConfig.Dynamic.UnreasonableModPrices)
         {
-            if (!itemHelper.IsOfBaseclass(itemTemplateId, key) || !value.Enabled)
+            if (!value.Enabled || !itemHelper.IsOfBaseclass(itemTemplateId, key))
             {
                 continue;
             }