This sounds a lot like the idea of nostr:npub1pages5yhmncmmfxuza9f9fx68fju0nxnewtlffzrapsufax5mv0sznuw9d -- is this going to be open sourced? how about we make these type of results available to seed finding relays for npubs and other tags?

That "best set of relays to be used to fetch notes for each Nostr user" is a very good question to solve.

nostr:npub180cvv07tjdrrgpa0j7j7tmnyl2yr6yr7l8j4s3evf6u64th6gkwsyjh6w6