I would also like to see NIP-65 support in Iris. I'll be adding it to Nos along with the gossip model. It could definitely work in kind 0, although most apps are currently using kind 3, and the kind 3s can get kind of large with all the pubkeys, so the rational break it out and keep it lightweight makes sense. The cheaper it is for relay owners to host relay lists the better greased the wheels of Nostr will be I think.