Hey dumb question, do you think you could implement a 3 shear rotation with grid snapping to preserve pixels in rotations?
It's an old technique used on retro consoles to preserve the important pixels on sprites instead of making unique sprites for rotations, there's a really cool video by standup maths on youtube on how it works.
I'd love to be able to rotate artworks without ever losing any pixels (except for those lost to the edges of the canvas, I guess :P)