How does this work? How do you host pixelfed.domain.com and mastodon.domain.com together in the same domain, with queries for “@user@domain.com” to the webfinger host path?
I’m other words, how does the querying application know which resource it needs? How do you know that a pixelfed instance will get the pixelfed resource versus the mastodon resource?
I’ve thought about doing this. It seems simple enough, though it would need a front end to be user friendly. I could build the rest api pretty quickly.