rel level stuff is generally meta…

rel level stuff is generally meta data about an http page, similar to http headers, but in the page itself, normally in the head

that's so that the protocol and the content have clean separation, and can then be delivered over any transport

what you would do in the json would be to have something like "creator" or structure it as the mainEntity of the page, the data structure inside the json is quite flexible

rel=me is a hack that says the page is the same as a person. you might get away with it in indieweb, but in a multip protocol system clean separation scales better