Hi psingleton,
This week I built a MacOS standalone app for OM playback, with microtonal support. I did it precisely because some of my students have been wanting to start learning OM but have run into the same issue you’re describing.
Admittedly, the one I made is not as fancy as R-udp player, since it doesn’t use fluidsynth~ but feel free to try it. You can download it from my website, at the very bottom of the page: https://www.felipe-tovar-henao.com/projects
It’s called miniOMsynth — Hope that works for you. Let me know.