Someone really should let him know that if it's the clients generating the key he's worried about, that can absolutely be done locally, even on an airgapped system if you really want to go full blown paranoid about it. https://github.com/jeffthibault/python-nostr has the library and a use case for generating the keys. Clients just generate keys as a convenience, much like how signers will generate bitcoin keys for you -- you can always generate them yourself.