A few comments, further cleanup. A few TODOs handled.

Penumbra/Mods/Manager/Mod.Manager.cs

@@ -6,16 +6,22 @@ namespace Penumbra.Mods;
 
 public sealed partial class Mod
 {
-    public sealed partial class Manager : IEnumerable< Mod >
+    public sealed partial class Manager : IReadOnlyList< Mod >
     {
+        // An easily accessible set of new mods.
+        // Mods are added when they are created or imported.
+        // Mods are removed when they are deleted or when they are toggled in any collection.
+        // Also gets cleared on mod rediscovery.
+        public readonly HashSet< Mod > NewMods = new();
+
         private readonly List< Mod > _mods = new();
 
+        public Mod this[ int idx ]
+            => _mods[ idx ];
+
         public Mod this[ Index idx ]
             => _mods[ idx ];
 
-        public IReadOnlyList< Mod > Mods
-            => _mods;
-
         public int Count
             => _mods.Count;
 
@@ -29,6 +35,7 @@ public sealed partial class Mod
         {
             SetBaseDirectory( modDirectory, true );
             ModOptionChanged += OnModOptionChange;
+            ModPathChanged   += OnModPathChange;
         }
     }
 }