It looks super interesting, I will try to read it all this week.
As a side-node regarding UV coordinates, I was facing a problem for Sonic Z-Treme : how to animate textures when I have like 10 different variations of the same texture, with different sizes (for LOD), spread across 2 different color system (CLUT vs 256 banks).
So I found a solution : manipulate the texture's adress in VRAM to scroll it line by line a generate an animation.
The result is that, instead of storing 8 x the same texture to have a 8 frames animation, I can do very smooth animation, like 32 frames for a 32x32 texture.
https://youtu.be/9hBK7jcqHBYWhile not exactly texture coordinates, it's still possible to play a bit with the adresses to create similar effects, with some restrictions of course.