Bellarminists can't address the problem of when heresy has become sufficiently manifest in order for deposition to happen.
1) Joe Sixpack reads a papal encyclical and determines that it's heretical.
2) Several priests and a bishop decide that the pope is a heretic.
3) Several bishops determine that a pope is a heretic but most other bishops disagree with them.
4) 49% of the Church's bishops consider the pope a heretic, but 51% don't.
5) 51% of the Church's bishops consider the pope a heretic, but 49% don't.
6) 90% of the Church's bishops consider the pope a heretic, but 10% don't.
7) General Council declares the pope a heretic and to have lost office.
Right now we're somewhere between #1 and #3. I'm pretty sure that you had more bishops who considered the pope a heretic for defining infallibility at Vatican I than you have bishops today who consider the V2 papal claimants to be heretics.
And here's the next problem. What HERESY have the V2 papal claimants embraced? I'm not talking about errors but about actual heresy. Religious Liberty? While it's a grave error, it's not heresy, strictly speaking, and I've seen a number of people jump through hoops to explain why it's not even erroneous. Ecuмenism? That's a practical thing and not theological.
Religious indifferentism, this notion that people can be saved in any religion? But, wait, +Lefebvre and most of the Trad bishops say the same thing, that people of any religion can be saved.
V2 ecclesiology? But, wait, the anti-Feeneyite Trads have the same ecclesiology. Is it heretical? Are they heretics also?
While Bergoglio might be a special case, since he stands up there and almost brags about being heretical, his predecessors insisted that there was some continuity between their teaching and prior Tradition. So who's going to sort it all out and establish definitively, with the certainty of faith, that their claims are bogus and that they are in fact heretics? But, then, what happens if, once the Church does definitely establish heresy, the V2 papal claimant were to recant? Pure Bellarminism would have it that they were already deposed once it became manifest, so there would have to be a new election.
You guys pretend that it's all simple and black-and-white ... but it is anything BUT....