I don't know if it's you or skeeter who did this, but at some point you were hating on Cabba and said basically that you don't want screen time or focus to be wasted on Cabba because he has no character. But focus is how you get to know and like characters. Characters can't "build character" without some screentime and focus. The *focus* that U6 already got is why you are so interested in U6.
You would likely care more about some of the other universes if the show previously had explored them more significantly. You'd find characters that you like, aesthetics, societies, planets, anything.
Which is why I think this arc would have a lot more wight if we actually got to know at least some of these other universes better. Yeah I don't really care about any of them now, and that's the problem. A problem that had a remedy. If those universes were explored more in other arcs, I would care a lot more about the fate of those universes, and thus enjoy the arc a lot more.