That’s exciting Ezekiel! Best of luck with your project!
I would recommend taking advantage of the OCA (Open Cell Animation) format, so users can export/import their x-sheet timing data, etc.
As I’m sure you are already aware, we are going to implement coloring with fill etc as a free update (in version 5.1 or 5.2) soon after the version we are working on now (5.0).
Thanks a lot Ezekiel!