Yeah, triangle mesh library and NURBS are very different, they do different things. Interesting to know that the solvespace folks wanted to try integrating manifold. Feel free to open an issue or discussion if needed, there were many changes as manifold was actively developed and gaining more users.

I am also interested in having a simple constraint solver for some kind of constructive geometry useful for CAD modeling, but not necessarily a full-fledged NURBS kernel. I think it can be interesting for text-based modeling, probably similar to some of the CadQuery APIs.