Is possible to validate track player data (target object) or override editor? I use [TrackBindingType(typeof(UnityEngine.Object))] to support multiple types in track.
Yes. You can create a TrackEditor for your custom track and you will be able to override the GetBindingFrom method. This method will be called when an object is being dragged on your track. The return value can be any object/component that you want to bind to your track. Edit: GetBindingFrom is available since Timeline v1.5