don't save windows that haven't changed

Dalamud/Interface/Windowing/Persistence/PresetModel.cs

@@ -49,5 +49,13 @@ internal class PresetModel
         /// </summary>
         [JsonProperty("a")]
         public float? Alpha { get; set; }
+
+        /// <summary>
+        /// Gets a value indicating whether this preset is in the default state.
+        /// </summary>
+        public bool IsDefault =>
+            !this.IsPinned &&
+            !this.IsClickThrough &&
+            !this.Alpha.HasValue;
     }
 }

Dalamud/Interface/Windowing/Persistence/WindowSystemPersistence.cs

@@ -41,7 +41,17 @@ internal class WindowSystemPersistence : IServiceType
     /// <param name="window">The preset window instance.</param>
     public void SaveWindow(uint id, PresetModel.PresetWindow window)
     {
-        this.ActivePreset.Windows[id] = window;
+        // If the window is in the default state, don't save it to avoid saving every possible window
+        // if the user has not customized anything.
+        if (window.IsDefault)
+        {
+            this.ActivePreset.Windows.Remove(id);
+        }
+        else
+        {
+            this.ActivePreset.Windows[id] = window;
+        }
+
         this.config.QueueSave();
     }
 }