Aside from Fusion360, is there a Free (or FOSS) cad package that uses breps and is scriptable?

Fusion360 is just stupid fast at perforations and sophisticated modeling constructions via its python API. I use it because it works well, but I'd be happier if I didn't have to maintain that Autodesk dependency...

freeCAD is brep based and scriptable.

FreeCAD via AstoCAD (https://www.astocad.com/ - 4€/month) is quite more user friendly too, compared to the vanilla experience, for those who want to do CAD sometimes and forget things between uses. It's made by FreeCAD contributors who push things upstream too.

Eh. Since the 1.0 release of freeCAD, the UI has been greatly improved. Also subscription services are inherently a turn off.

I see it as a donation to developer who work on FreeCAD, not a "subscription service", just a different way of funding FOSS.

I'd agree that FreeCAD's UI isn't horrible, but it is a lot to take in at a first glance, and for people who don't use it frequently. If I was using it daily, I'd probably prefer FreeCAD as-is too, better feature density and everything at a glance.

OpenSCAD nightly using the Manifold engine is a lot faster than the CGAL crap the stable version ships with

I am learning build123 and skipping OpenSCAD altogether

just build it from source, its like night and day! thanks for the tip