I had a pseudo-plan for something like this but for reasons related to privacy I had two types of chatrooms:

* regular chats, existing only on the server, no leaking the chat transcript except via users, but never via server to server.

* chambers: a global chatroom, located at a server, maybe with a MQTT anyone could subscribe to.

This never left the early planning stages though, but I thought the segregation between federated chatrooms and regular chatrooms was of interest to keep in sync with IRC open but closed nature of chats.

That seems to be similar on this one. &room is local, while #room is federated.