Evaluating multiple Timelines simultaneously

What I’d really like a way to have a custom PlayableDirector. A mode where the playing is custom, but is guaranteed to be advancing so that everything works like normal. This would allow me to implement my FixedUpdate mode that I wanted in this thread:

I’m circling back to this now, because while using Evaluate in my FixedUpdate works, it’s massively slow and losing out on AudioClips is really a bummer. Maybe you could point us to the place in the source where we could add in a different mode alongside GameTime and DSPClock?