Simplified per face uv and uv image allocation

Basically I would like to see that users could have the possibility to allocate uv sizes per face and group them based on that (32x32, 64x64 grid, etc..) and allocate an area from uv for that or lay them above each other if same color area is to be used.

We have already face id's available for grouping. This way user can select which faces use which size. Then you would have the possibility also to select if the pixels are blended on both sides of the facing edge of face.

This would only work in quad mode best? And does it cause graphical error if subdividing mesh?