Good news: After 10 hours of refactoring, everything works on both iOS and macOS:
See movie: Dropbox - TRAnimation macOS and iOS.mov - Simplify your life
The split between the mobile and desktop controls is handled neatly with patterns:
(Though there seems to be a bug in iOS project that prevents the desktop control from being ignored the mobile project, while the mobile canvas control can be ignored in the desktop project)
Handling Timer.Run vs Timer.Action:
And finalyl, Font differences between Desktop and Mobile are handled.
So basically, everything is handled transparently behind the scenes, allowing you to write your sprite framework code for either platform.
This is one step closer to being released but I’m not yet sure what type of license to use.