we should be able to get that with NIP-66 and the stuff  @sandwich built:

nak req -k 30166 -t N=50 relay.nostr.watch -a 9bbbb845e5b6c831c29789900769843ab43bb5047abe697870cb50b6fc9bf923 should get it, but I see it's returning non-NIP-50 relays 🤔

kind:30166 with "#N": ["50"] should get that info 😀 

 Hmm, I just ran a test and more or less got what I expected. Here's the test result:

https://gist.github.com/dskvr/6036030fb5302e8a519e1d73d5f790c4

Can you provide replication instructions? 

 You're missing `since` btw. 

 Also don't you need to encapsulate `50` with double quotes in nak? `"50"` :D