We have a solution if your contacts have a nostr address: you can store your relays in your nip05 metadata. Unfortunately i don’t think many nip05 providers set this up properly from your relay list.
We currently rely on a few large hub relays to store relay lists, but as the network gets bigger a dht might make more sense. Not sure what nostr:npub180cvv07tjdrrgpa0j7j7tmnyl2yr6yr7l8j4s3evf6u64th6gkwsyjh6w6 thinks.