Anyone interested in the latest urls just subscribes to the service's pubkeys publication of this kind 11111 event.
Then 'isrobosatsdown' becomes 'whereisrobosatscurrently'...
https://github.com/nostr-protocol/nips/pull/1585
Would this be useful for your situation? You can self-publish and update url's as they become available or go down.
Discussion
That's really interesting, it would still require an extra softwareyolto do the match, buy really helpful. Would be nice to have a browser extension that store pubkeys and takes care of updating bookmarks or resolve onions with the information found from these pubkeys
Good point, a browser extension could be really helpful here!