Yes, I say that because if the UOM teaches, as you said: "that the true Roman Pontiff will not fall into heresy or apostasy (defect from the Faith) because he is protected by the Holy Spirit" then we have no choice whatsoever in the matter - per the UOM we are bound to follow the pope because he is always protected by the Holy Spirit. Which means that trads are wrong and have been wrong and the NO is the true religion and has been since this so-called "crisis" started.
Also, I know that's the sede position, but with all due respect, in light of V1 that position is ridiculous.
V1 clearly defines when the pope is infallible. This definition *must* agree with the UOM or one of them is wrong - which is altogether impossible. All V1 did was define that which the UOM has always taught.
Referencing V1, I do not know how it is possible for anyone to say what you said - "if "heresies" were taught by "the Pope" himself, then that person was not a true Pope" because that implication is not in there.
Well, one thing is certain, the conciliar popes have most certainly taught/teach/promulgate heresies and errors. I mean, it is pretty basic, when something is taught that is contrary to the faith, to what the Church has always taught, it's heresy - no matter who preaches it.
All I have to do is repeat the dogma of papal infallibility - per the dogma the only time the pope cannot err is when he defines a doctrine ex cathedra. For whatever reason, sedes feel it necessary or they are obligated to add on and on to the defined dogma.
Note that it is only after proclaiming that the Church has additional criteria and requirements above and beyond the infallible definition of V1, that they form their conclusion.
As I have said, I hope the sedes are right. I do not think they are, but for their sake, I certainly hope they are. FWIW, I have a a number of departed sede faithful that I pray for their souls every day and have done so for decades. I really do hope they're right.
The Sede position is not ridiculous. It may be incorrect based on the historical facts. But doctrinally, the Sede position is in line with the traditional teaching about the Pope.
That a papal claimant (note I did not say Pope) truly teaches a "heresy," then that is proof, in and of itself, that the papal claimant is not a true Pope. The Sedes are absolutely correct on that. That he either was never validly-elected because of some secret defect or whatever.
The idea that a true Pope could be a "heretic" is asinine and blasphemous. It mocks Jesus's promise that Peter is the "rock on which the Church shall be built." Every successor of Peter is that "Rock," not just Simon bar Jona.
But there are many examples of "Peters," starting with Simon bar Jona himself, that reveal the potential for human weakness in these men. The worst Pope might have been John XII (
https://www.newadvent.org/cathen/08426b.htm). From that CE article we read:
"John was accused of sacrilege, simony, perjury, murder, adultery, and incest, and was summoned in writing to defend himself."
Note, however, of all the sins John XII was accused of, heresy was not one of them. That is because the Holy Spirit does not allow the true Pope to be a heretic, in the proper meaning of that word.
But trads of all types throw around the word "heretic" as if it is the same thing as "sacrilege" or "impiety." Heresy is a defection from the true Faith. Sacrilege or impiety is an horrible offense against God or sacred things. They are not the same thing as any manual of Moral Theology will tell you.
The other things that trads of all types do is rush to judgment about the actions of the Popes, as if they know all the details of exactly what happened in the distant past. This is arrogant.
We don't know if Paul VI understood exactly what the Freemason infiltrators in the Vatican were doing. Maybe he did. Maybe he didn't.
And we don't need to rush to judgment on that. We can know that the false Novus Ordo sacraments are to be avoided simply because the Church has always taught that the "substance of the sacraments" cannot be changed, by the Pope or anyone else. They are counterfeits and must be avoided, no matter what an evil or confused or weak or ignorant Pope might say.
The Pope cannot overrule a previously laid down irreformable, infallible teaching of the Church. He doesn't have that power as
Pastor Aeternus says here:
"For the Holy Spirit was promised to the successors of Peter
not so that they might, by his revelation, make known some new doctrine, but that, by his assistance, they might religiously guard and faithfully expound the revelation or deposit of faith transmitted by the apostles."