You used the word "brazen." Good word, meaning he's not ashamed of "coming out" so to speak. The other guys you mentioned, if heretics at all, were more "secretive." They stayed "in the closet," as they say. You might even use the word "occult" to describe the "heresies" of those predecessors of Bergoglio.

Miracle of the Sun beat me to it.

Yes, Ratzinger was/is the poster child for Vatican II Modernists who left us with miles of terrible writings.  Not 'secretive' by any stretch.

Yes, glad you mentioned Bergoglio, since he's the only one that really matters at the moment.

You used the word "brazen." Good word, meaning he's not ashamed of "coming out" so to speak. The other guys you mentioned, if heretics at all, were more "secretive." They stayed "in the closet," as they say. You might even use the word "occult" to describe the "heresies" of those predecessors of Bergoglio.

But Bellarmine's Fifth Opinion, the one he calls "true," says that "secret" or "occult" heresy is not enough for the ipso facto loss of office. Those who hold the Second Opinion, rejected by Bellarmine, hold that "secret" heretics lose their office. Bellarmine says,

So, one will need "to prove" that a lawfully-elected Pope manifestly taught formal heresy and was obstinate in that teaching before he loses his office. That is, if you use Bellarmine and Canon Law as your guide.

Many hours have been spent digging through obscure writings of those earlier Popes. They bring up many statements that approach heresy. But they fail to establish manifest formal heresy as required by Bellarmine. With Bergoglio, we do not have that problem.

To be fair, St Robert Bellarmine actually didn't believe a true pope COULD fall into heresy because Christ would not allow his faith to fail. 

https://sspx.org/en/news-events/news/question-papal-heresy-part-6b

Fr. Gleize splits the matter in two: the prudential and the speculative.

1. Prudential: Archbishop Lefebvre said "recognize" and pray for "the Pope," meaning whoever the Pope is. Don't discuss deposing or loss of office. Not important. Just pray and "resist" on certain things to be decided by "prudence."

2. Speculative: Gleize takes Billot as his guide over Bellarmine and Cajetan. He says that Billot makes it clear that "Cajetan’s explanation in reality does not avoid saying that the Church is above the pope." This principle, then, that one can NEVER SAY that "the Church is above the pope" is sacrosanct for Fr. Gleize and the SSPX. Therefore, all Speculative attempts (e.g., Bellarmine, et. al.) are worthless to the extent that they violate that principle.

So, as I see it, the SSPX position, formulated by Fr. Gleize amounts to The Third Opinion listed by Bellarmine. Since there is actually no way to resolve the speculative problem, Fr. Gleize would say, one must resort to the prudential solution of Abp. Lefebvre, i.e., to always Recognize and Resist (when we feel like it).

Fr. Paul Kramer, in Volume II, defends Joseph Ratzinger from those who accuse him of public manifest formal heresy.

"Therefore, it cannot be maintained that Joseph Ratzinger is a heretic, on the basis of the specious and false pretext that he has asserted heretical disbelief in dogmas by incorrectly explicating those dogmas which in their proper content include in themselves the notion of created substance composed of matter and form, or that he has explained other dogmas in such a manner that involves his argument in some basic contradiction. He has professed belief in the dogmas, but has explained them in a logically incoherent and sometimes contradictory manner, but without directly, immediately, explicitly, and knowingly asserting disbelief in the dogmas themselves, which alone would be an indicium of formal heresy that constitutes proof of formal heresy; yet, as I have explained, his exposition on their meaning contain propositions which, considered in themselves, contain material heresy in that the contrary part of his contradictory assertions are opposed to the dogmas which he does profess, and, due to his faulty understanding of the philosophical concepts which underlie some dogmas, he does not always profess those dogmas according to their proper sense as the Church has defined them. Hence, there are not to be found the indicia of formal heresy in the writings of Joseph Ratzinger, who is still at present, Pope Benedict XVI, the Vicar of Christ on earth."

Kramer, Paul. On the true and the false pope: The case against Bergoglio (pp. 602-603). Gondolin Press. Kindle Edition.

I agree with Fr. Paul Kramer.