> This is the special thing about OpenSCAD design is they figured out how to build an abstract syntax tree that could either be sent to OpenCSG, CGAL (old engine), Manifold (new engine), or even the bare bones 'ThrownTogether' renderer (ancient engine on machines with no gpu that just draws 'negatives' as green blobs iirc).

Mostly.

I've still had several instances when drawing curved solids that the OpenCSG renderer worked well with (visually) but when it came to render-time, there was something wrong. It is very hard to debug things, or at least I found it so, when it goes wrong like that.