RequestAnimationFrame is in the making. I had it but then wanted to create a wrapper to allow easy cleanup. Will let you know when done. More to come...
Yes, as it should only be used as a value generator in the GUI to rig up something. Would love custom timeline values that we can register on a project basis.
@jonathan Groundhog Day... I had that same idea in 2015 
see Animating custom CSS properties - #7 by MaxZieb