I was using RiF through Revanced and it logged me out and trying to log back in threw a User-Agent error. Reddit on web went down about 15 minutes later. It seems an unlikely error to be thrown because the site's going down (and I've never seen it using RiF legitimately).

I'd imagine it just works the same as Co-Pilot on Xbox where you just effectively connect two controllers to one 'port'. Both have full control over everything for one player. I've used it on Xbox for games that are intended to be pass the pad, but we can't be bothered with actually passing a controller back and forth.