> Matrix is interesting, but I'm waiting for their new Go implementation (dendrite?). The deployment for matrix feels like it's heavier than it should be. I feel like I should be able to spin up a process and point to the port and call it a day.

Sounds like you, like me, have had your brain broken by the ease of deploying Go programs :) The current Synapse server is written in Python, so it's a bit of a trial. That said, I run it on a tiny linode instance and it Just Works after maybe an hour of fiddling around (I seem to remember something about DNS records being the fiddliest part to get right).