I interpret kind 2 to say "Hey this is a great relay, you guys should try it", rather than "If you want to find my posts in the future, I expect to be putting them here". kind-2 also only has a single relay in the contents.

kind 10001 in nip 23 (pr 32) would work. I'm not excited about parsing the runes language, but it would serve.

Currently gossip does excessively complex tracking of stuff because "here is where I post" information is not easily and widely available.