In a happy eyeballs analogy, one approach might want to connect to all listed IPs at the same time, and return the first that responds and is read write.
I would hope that "the first" read write is also "the only" read write. If you have a multi-leader situation, you almost certainly want to be quite precise about who connects to what, and not leave that up to the whims of the network gods.
I'm still a big +1 to the original proposal in this thread, and don't think it would be incompatible with happy eyeballs. Although I would think the latter would be quite wasteful, as we are not simply checking for a response, but doing a whole connect/authenticate/get-status dance. Is a quicker response more important than querying every IP in the list every time? I dunno. Maybe that's a future argument to target_session_attribs.[1]
[1] Yes, I know, but that's what the name should have been. Or even "attributes"
