hodlbod on Nostr: No, the chats aren't encrypted, they just rely on the relays to enforce access ...

No, the chats aren't encrypted, they just rely on the relays to enforce access control. There is lots of interest in using nostr/mls for that though, which I think is pretty promising. See https://github.com/nostr-protocol/nips/blob/master/EE.md for that spec. What approach are you taking?