I do really appreciate the focus of MyPaint, and that is one of the main reasons I enjoy using it. The line on the website, "It lets you focus on the art instead of the program." is one of the reasons I downloaded the program to start with, and you are definitely adhering to that premise!
I was thinking more along the lines of extending the layer model rather than using a different one. I have yet to look at the code; so maybe this isn't the correct way to approach the problem. If I were to hack the code to do what I want, what approach would you recommend?
I mainly just want to be able to draw one frame with MyPaint brushes and look at another frame or frames simultaneously. I would ultimately be using other software to combine the frames; so, any functionality beyond that and flipping through frames manually would be fluff to me.
How easy/challenging do you think it would be to add these things?