For the foreseeable future I'm just going to be working on stability/performance, but eventually I will get back to adding more cool physics stuff. It's not open-source, but certainly I'd enjoy talking to a real physicist (I'm something a couple notches below armchair-level). Hit me up at evan@anukari.com sometime if you like!
I was using the demo just now: the sounds you get out of this are actually better than I expected! And I see what you meant in the videos about intuitive editing, rather than abstract.
Although, I was often hitting 100% CPU with some presets, with the sound glitching accordingly. So I could experiment only in part. I'm on an M1 Pro; initially I set 128 buffer sample size in Ableton but most presets were glitching, I then set to 2048 just to check for improvement, which it did, nevertheless it does seem a bit high. Maybe my audio settings are incorrect? I can give more info later if it helps you.
Yeah performance at low buffer sizes is a big challenge, generally I recommend 512 or higher, which I know is not great but right now it's the most practical thing. The issue is that the computation is all done on the GPU, and there's a round-trip latency that has to be amortized. One day I'd like to convince Apple to work on the kernel scheduling latency...