Jeremy/Assets/Scripts/TrackStuff/MyButtonTrackMixer.cs

using UnityEngine;
using UnityEngine.Playables;

public class MyButtonTrackMixer : PlayableBehaviour
{
    public override void ProcessFrame(Playable playable, FrameData info, object playerData)
    {
        var myButton = playerData as MyButton;
        
        if(!myButton){return;}

        myButton.isActive = false;

        for (var i = 0; i < playable.GetInputCount(); i++)
        {
            var inputWeight = playable.GetInputWeight(i);
            
            if (inputWeight > 0)
            {
                myButton.isActive = true;
            }
        }
    }
}