That could be done but what if some relay doesn't use the flag? And what if a client doesn't respect the flag? Ultimately other clients will have to work around this anyway. There are tons of other issues that could arise from kind:10002 relay lists: - the relay may be offline - the URL may be invalid - the relay may have banned the user - the list may be outdated and the relays where the list is being fetched may have banned the user and continued to serve old outdated That's why I think any Nostr app above some threshold of complexity must eventually implement a scheme like seen in

how nostr works

relying on relay hints from others and decreasing scores for relays as they're perceived to not return new notes from the target users, so new relays get tried until some succeed or until a new better relay list is found.