All Catholics are required to be completely dogmatic on the issue
Can you prove that logically? I mean I figure you probably won't bother.
I realize that ordinarily you're supposed to accept the Pope that's universally accepted. The problem is that Francis is no more "universally accepted" than Vatican II is. With that being said, and with all the opinions of theologians on what happens to a heretic pope, I don't see how its *impossible* for some future Trad Pope to be like "yeah actually Francis was never really Pope, he wasn't Catholic."