I’m aware regular Beeper can be self-hosted, but Beeper Mini can too?
The difference between old and new is that all the services on the old one rely on Matrix bridges and the new one will not. They claim iMessage, Signal and WhatsApp will all be working on-device. So those obviously won’t be self-hosted. The rest they have yet to decide exactly how they will implement them but Matrix is going to be part of it.
Brad Murray said the end goal is to have everyone messaging each other directly on Matrix.