created option to override values before UpdateState is called

osu.Game.Rulesets.Osu/Mods/OsuMod.cs

@@ -44,6 +44,14 @@ namespace osu.Game.Rulesets.Osu.Mods
                 d.ApplyCustomUpdateState += ApplyHiddenState;
         }
 
+        protected void ApplyHiddenValues(DrawableHitObject drawable)
+        {
+            if (!(drawable is DrawableOsuHitObject d))
+                return;
+
+            d.FadeIn = preEmpt * fade_in_duration_multiplier;
+        }
+
         protected void ApplyHiddenState(DrawableHitObject drawable, ArmedState state)
         {
             if (!(drawable is DrawableOsuHitObject d))
@@ -58,8 +66,6 @@ namespace osu.Game.Rulesets.Osu.Mods
             // new duration from completed fade in to end (before fading out)
             var longFadeDuration = ((d.HitObject as IHasEndTime)?.EndTime ?? d.HitObject.StartTime) - fadeOutStartTime;
 
-            d.FadeIn = fadeInDuration;
-
             switch (drawable)
             {
                 case DrawableHitCircle circle:

osu.Game/Rulesets/Objects/Drawables/DrawableHitObject.cs

@@ -120,6 +120,9 @@ namespace osu.Game.Rulesets.Objects.Drawables
 
             State.ValueChanged += state =>
             {
+                // apply any custom values
+                ApplyCustomValues?.Invoke(this);
+
                 UpdateState(state);
 
                 // apply any custom state overrides
@@ -250,6 +253,11 @@ namespace osu.Game.Rulesets.Objects.Drawables
             nestedHitObjects.Add(h);
         }
 
+        /// <summary>
+        /// Bind to apply custom values.
+        /// </summary>
+        public event Action<DrawableHitObject> ApplyCustomValues;
+
         /// <summary>
         /// Bind to apply a custom state which can override the default implementation.
         /// </summary>