Interesting, but doesn’t this need some centralized coordinator to match the clients to the servers (via the “connector” string)?

What happens if I try running a server with the same connector string as someone else? Is it encrypted?

The lnurl/lightning-address protocols are based on small json payloads. It will be simple for every smartphone wallet to send them as “nostr dms” (with a different ephemeral kind), it will be encrypted, and will also be reliable if you use multiple relays.