All of our NIP-42 stuff is custom. Most paid relays only restrict write access but not through NIP-42, just by keeping a pubkey whitelist or other restrictions. I believe the rust nostr relay has a NIP-42 implementation but I haven’t used it.

Thanks for the fast reply Mazin, so cool. I think I have that rust relay up and running. Docs make me wonder if the NIP-42 implementation is focussed on write rather than read. If you have custom rolled yours, was stirfry your starting point? Do you have any plans to share or license your code? I am not sure what's involved in that, I am just trying to figure out an entry point to explore further.