Looks interesting! I'm currently, and thankfully, not responsible for any infrastructure where this would be useful, but will definitely check it out the next time the need arises.

TeamViewer is (both technically and commercially) awful, and getting rid of it is always priority #1 when taking on a new environment. You always run into fun stuff like 'oh, yeah, this 4-years obsolete version is running on our main accounting server all the time, as that's the only thing the vendor supports, and they need to be able to get in at all times'... 'yes, indeed, using only a 4-digit PIN, why do you ask?'...

Being able to supply your own RustDesk rendezvous/relay server is especially interesting to me, as features like proper SSO-linked 2FA, a log of who accessed what from where (hopefully including file transfers), and alerts on large data flows becom a lot easier to implement that way.