> the SMLib kernel they are currently porting to Rust from Nvidia is currently about a decade behind OpenCascade, nevermind Parasolid/ACIS as they are still converting all geometry to NURBS instead of preserving analytical geometry , which means that their initial development is easier but it creates a near infinite amount of edge cases once they start going heavy into booleans and fillet/chamfers.
Where are you getting this information from? Booleans and fillets at least use analytic geometry:
Analytic fillets:
https://gitlab-master.nvidia.com/omniverse/solidmodeling/-/b...
Analytic surface intersection (example of sphere/cone) used by booleans:
https://gitlab-master.nvidia.com/omniverse/solidmodeling/-/b...