With all the debate raging on the different positions regarding the Papacy, the simple truth of the matter is that the Church has never officially defined what happens in the case of a heretical pope. There dozens of possible variations of opinions, anywhere from he's immediately gone to he remains Pope and there's no way to get rid of him til he dies, all of which can be legitimately held by Catholics ... so long as it doesn't violate any known Catholic principles that have in fact been taught by the Church. So, for instance, no legitimate principle can have it that the Pope as Pope can actually be deposed by the Church, since it's taught that there's no higher authority on earth than the Pope and that the Pope cannot be deposed.
With that said, I could hardly care less what opinion you have on this issue. You're perfectly entitled to it.
BUT ... don't tell me that a legitimate Ecuмenical Council taught errors (or even heresies) to the Universal Church and don't tell me that a legitimate Pope promulgated a Rite of Mass that displeases God and is harmful to faith. Don't tell me that it's OK for Catholics to go so far as to break communion with the legitimate hierarchy in order to reject this Magisterium and Universal Discipline. Don't tell me that the Magisterium and Universal Discipline of the Church have gotten so corrupt that we're almost required to break communion with the Church in order to save our souls. That is nothing other than the defection of the Catholic Church.
Now, if you want to say that 1) V2 can be reconciled with Tradition through some hermeutic of continuity and the New Mass when offered as intended in Latin isn't particularly bad or displeaseing to God, or that 2) Montini was replaced by an imposter who fraudulently promulgated these things, or that 3) Montini was being blackmailed due to his prior ɧoɱosɛҳųαƖ activities, or that 4) someone else was signing these docuмents, or that 5) Montini was just a holographic projection and the Illuminati controlled everything, or that 6) Cardinal Siri was elected pope and impeded the legitimate election of most of the V2 popes, or that 7) Paul VI had no legitimate authority due to heresy, or at least doubt/suspicion, or had some authority but not teaching authority, or was just materially pope. I would rather buy the holographic Montini theory than smear the Holy Catholic Church by saying that Vatican II and the Novus Ordo Mass are products of the Church.