I am using SolveSpace for my 3D prints because I just don't have time to learn anything else. With SolveSpace I've been productive in like 2 hours after launching it the first time.
So far you've saved me like $500 in things I've printed instead of bought. Just last week I've printed nasal manifold for my DIY sleep monitoring setup. Replacement specs legs a month ago.
If you really make fillets and chamfers a reality, please don't forget to open donations.
I also appreciate the difficulty of generalizing chamfers/fillets. There's a reason that basically all FOSS CAD packages have struggled with it.
Could you decompile CAD, run it through an LLM, and call it a day?