openscad is parametric, it is very parametric. by some tokens it is more parametric than the "proper parametric modeler" it is however missing a constraint solver. that would be my dream cad software, a proper scene description language to model in and a built in robust constraint library so you don't have to program your constraints from scratch.

Any feedback is welcome. You can import and export step files. There is no support of assemblies, so I am not sure what you will get.

That’s fine. I do mostly 3D printing, so although I do have some interlocking models I don’t have awesomely complex geometry. But having STEP support ensures I can move my data about to some degree.