Hey, creator of Fornjot here. I had experimented with f-rep for years before switching to b-rep for the current iteration of Fornjot. I came to the conclusion that f-rep, while neat, is too limited for what I intend to do. I came to a similar conclusion regarding the mesh-based approach of CGAL.

I've written more about that here: https://www.fornjot.app/blog/why-fornjot-is-using-boundary-r...