yeah, this is an essential feature, and nobody is prioritising it as they should be

it's like putting a big fancy padlock on a shitty wood and cardboard gate, to add all this obfuscation to the messages when you could just have auth and not send out messages that don't relate to an authed user pubkey

really, you can't solve that problem any other way

the relay is acting as an untrustworthy intermediary when it doesn't have controls to prevent strangers reading your private messages