"You can also self host your own NIP-05 Identifier, but I am not really knowledgeable on that, although I think this option is for those who self host their own nostr relay, which I haven’t done yet."

I don't think you need to be running your own relay to host your own NIP-5, just to host a file (I believe in json format) in your domain server and then register it with one of the NIP-5 "providers".