I was just comparing to a more general socat-like server, but yea compared to Tor it'd still be a massive improvement and might have added benefits by being able to hide amongst other traffic on public infrastructure.

You probably wouldn't need any in that case as the relay will just dump them, your protocol would just be an application that uses nip01 as it defines kind ranges for ephemeral events... then yours is just an application with a specific kind, there's a few like that including ours: https://github.com/nostr-protocol/nips#event-kinds