Hmm what about NIP-05 with decentralized DNS? I think ZeroSync will enable that on bitcoin without needing to be a full-node, but we could test it with namecoin in the meantime.

The relay IP hosting the NIP-05 data can be updated on-chain. When you connect to it, you download the user’s list of currently selected relays.

A user could put this decentralized DNS in all their notes. Could even have two or three decentralized DNSes and put all of them in every note you post.

Downside is the user has to buy the domain and pay to update the IP when needed, but it does feel more intuitive at least.