nostr:npub1pages5yhmncmmfxuza9f9fx68fju0nxnewtlffzrapsufax5mv0sznuw9d is one such relay. There are a few others.

but until is trivial/common-place for users to be able to switch relays with minimal cost relays won’t specialize much further.

We also need a few changes to make clients not even attempt to request some data from certain relays (eg purplepages will never serve you kind:1s so ideally clients wouldn’t even ask for them)