> ...then again I did a search for a couple strings and ran across https://github.com/keshavdv/unifi-cam-proxy . It's the opposite direction of what I want (makes a standard camera work with Unifi Protect) but maybe contains the protocol details I'm looking for...

Actually, yes. I got lazy and just asked Claude Code to write a server, using that as a reference...and it worked. It was able to change the password and have it start streaming flv video. Not exactly a production-quality implementation but as a proof-of-concept it's quite successful.