The case of Pope Leo V:
http://www.newadvent.org/cathen/09159b.htmhttps://archive.org/details/thelivesofthepop01platuoft/page/n269It is supposed that Leo was universally and peacefully accepted, otherwise why would the Roman Pontifical list him as the 118th pope? Is that a dogmatic fact? But if it was a dogmatic fact, how did Christopher get possession of the Roman See after he put Leo in prison? Prior to 1961 (John XXIII), Christopher was listed in the Roman Pontifical as a true pope. So what does dogmatic fact mean? If the history of the papacy doesn't support the definition of dogmatic fact as proposed by the R&R folks, how do the R&R folks handle that? Do they just dismiss out of hand any contrary evidence?
And it gets worse, Sergius III was elected in opposition to Christopher (and presumably Leo too since he was still alive in prison) and according to some, Sergius put both Leo and Christopher to death. The Roman Pontifical (prior to 1961) listed all three of them as true popes. Leo -> Christopher -> Sergius. I'm not sure how the dogmatic fact theory can fit with this evidence. I guess you could deny that there was universal peaceful acceptance of Leo. But I could deny that there is universal peaceful acceptance of Frank. Not even the entire Novus Ordo hierarchy accepts him as a true pope. Is your opinion that there is universal peaceful acceptance of Frank also a dogmatic fact? Also, is it a dogmatic fact that the Novus Ordo hierarchy is the hierarchy of the Catholic Church? If it is, then Religious Liberty and Ecuмenism and "for many" are also universally peacefully accepted. And if there isn't universal peaceful acceptance, Frank can remedy that by excommunicating those who don't peacefully accept him. Problem solved?
Or how about this case?:
John XII -> Antipope Leo VIII (Leone) -> John XII (same J12) -> Benedict V -> (now true pope but same guy as antipope) Leo VIII
Figure that one out.
Or how about the case of Pope St. Eugene I?:
http://www.newadvent.org/cathen/05598a.htmhttps://en.wikipedia.org/wiki/Pope_Eugene_Ihttps://archive.org/details/thelivesofthepop01platuoft/page/n181He was universally peacefully accepted by the entire hierarchy of the Church. Except there was one problem. His predecessor, Pope Martin I was still alive and in prison and had not abdicated! The Roman Pontifical has Pope
SAINT Eugene I ascending to the papacy a full year after he had been universally and peacefully accepted by the hierarchy. Not until after Pope Martin I died in prison did he officially become the pope. So when did it become a dogmatic fact that Pope Eugene was the true pope?
So you dogmatic facters have some explaining to do. How can you in good conscience call traditionalists heretics for not believing that it is a dogmatic fact that Frank the Clown is the pope? I'm a heretic for not believing that a manifest heretic is a pope? That's rich!