Thanks, it`s good to see you keep things going forward.

As for me I would love to see fillet, offset and shell all together with ACIS because those operation fails in Rhino most often. So even having still errors but different ones could help me to fix those errors quicker if time is tight.

Have you thought about some rebuild edges, surfaces or matchcrv, matchsrf took from ACIS (if it`s possible to take it from kernel)?

ACIS has also some skinning operations which could be also helpful (maybe I`m wrong, maybe your current are better, that is open question).

Cheers!!