Compared to OCC these libraries seem like toys. They support basic functionality but lack the other 90% that OCC already supports. The problem I see is that co

Compared to OCC these libraries seem like toys. They support basic functionality but lack the other 90% that OCC already supports. The problem I see is that complexity goes up a lot if you go beyond the most basic shapes and operations. The upside of that is that if you manage to keep your problems very simple, it's quite easy to make a new geometry kernel that supports your subset quite cleanly and efficiently.