[jlkuester7]

At one point I seriously considered self-hosting a Rocket Chat [1] instance for very similar reasons. It seems to have a good balance of features, moderation controls, and polish while still being pretty straight-forward to host.

The main challenge I ran into was, of course, convincing folks to use it (instead of the "easier" forms of communication that they already had....).

1. https://rocket.chat/