Video for Mecha below, it was not there when you posted:
Your pyldraw3 is a key component of both Mecha and Nova, together with the shadow library from LDCad.
Parsing LDraw, collision detection and connectivity between different parts mostly rely on pyldraw3 for validation.
About your other project, legolization, I took a look at it, and I think it's a very interesting approach, I've been thinking for a while about solvers and how to predict stability, too!
However, so far didn't find anything that would fit in, due to the high amount of parts interacting in Mecha animations.
Tried a couple of solvers, but with +1000 parts, performance degrades drastically, and a divide-conquer approach I still didn't have a chance to try.
And about finding common ground for LEGO tool makers, sure!
What is currently happening with agentic AIs quickly evolving CAD capabilities will for sure benefit LEGO and LDraw tooling.