[MayeulC]

Ah, interesting, it looks like Dune3D is based on solvespace with opencascade: https://docs.dune3d.org/en/latest/why-another-3d-cad.html

I was going to suggest solvespace. It is very barebones, but was much easier to use than FreeCad for me. It also has constraints in 3D space, which I use a lot: https://solvespace.com/index.pl