It’s less canonically possible than you might think.
Sure, in that show they can jump dimensions. But in this AU, dimensions cannot be so easily jumped. Doing so weakens the walls between them, so nobody in any dimension in this AU can or will do this willy-nilly, or else they’d leave entire realities in tattered messes.
So in this AU, it’s pretty canonically established that realities aren’t jumped. They can be glimpsed and perused if something has the power. Something with that power *could* hop across and back again, but there would be risks and consequences for it, so stuff generally doesn’t.
So yeah, we don’t do any crossovers in actual TAU canon for this reason, so you won’t see any fic or art for it on this blog, but you guys can always do this stuff and put it on the tag or on AO3.