I actually bought Plasticity early on, but bailed, because I found the UI confusing.
I was a bit more successful with Dune3D: https://dune3d.org (see the discussion I made on Github about working through the tutorial).
That said, OpenSCAD is more my speed, and I've been using it for a long while now, and have even gotten started on a library for the new OpenPythonSCAD, Python-enabled fork: https://pythonscad.org