I don't think they are that different. Both strings are using URI schemes and share many of the same arguments. It's just a matter of who initiates the authentication flow. If everyone runs something like NIP-46 (including client sites) then it essentially becomes sessions + permissions managment for peers, with the connect strings as an out-of-band way to initiate the session. It can be bidirectional. Once a session is established, the methods available can be anything. I'm planning to add bitcoin and lightning methods.