Sorry, Ambrose, I really don't want to get into this on this thread. We've gone over this before, and your thesis is problematic for at least five reasons, being expressly contrary to one defined dogma and the resuscitation of a proposition condemned at Constance. Your theory of how Apostolic succession can be continued without the Petrine succession is contradicted, among other sources, by cuм Ex, as I will mention in a new thread. (Even the suggestion of the same is an affront on the Church's monarchical constitution, only a Successor of Peter can make formal Successors of the Apostles, otherwise Peter is not the Rock on which the Church is built).
The Church is indefectible ... in her monarchical constitution (principle 4), comprising governing power i.e., jurisdiction, hence Vatican I’s profession that Peter will have perpetual successors ... is indefectibility preserved if there is no pope since 1962 or if there is no one with ordinary jurisdiction whom the sedevacantists can point out as such?
And though a sede vacante certainly cannot be prolonged beyond the point when all bishops appointed by the last Pope die, that does not mean that it can necessarily be prolonged up to that point. If all remaining Roman clergy or Ordinaries recognize a single candidate, it is impossible that the Church be in a sede vacante. You must profess communion with these to remain in the Church, and since they profess communion with the Pope, you must profess communion with him. Therefore, it is impossible, as all theologians teach, when all the authorities of the Church profess communion with the Pope, for the Pope not to be the Pope.
God will never allow the whole Church to recognize as Pontiff someone who is not really and lawfully. Thus, as long as a pope is accepted by the Church, and united with her like the head is united to the body, one can no longer raise any doubt about a possible defective election
Ecclesia Militans, canonizations are dogmatic facts, in the judgment of which the Church cannot err. That the Church is infallible in Her judgments is itself a revealed truth and the object of this judgment, inseparably connected with revelation and contained in it not formally but implicitly, is called the secondary object of infallibility.
To the secondary objects of infallibility belong... the canonization of saints, that is, the final judgment that a member of the Church has been assumed into eternal bliss and may be the object of general veneration.
... then a further decree may be issued by which the Pontiff defines that the person is a “Saint” and is to be honored as such in the whole Church with public veneration. No writer of repute doubts that this last decree of Canonization is an exercise of the infallible authority of the Church
To suppose that the Church can err in canonizing, is a sin, or is heresy, according to St. Bonaventure, Bellarmine, and others; or at least next door to heresy, according to Suarez, Azorius, Gotti, etc.; because the Sovereign Pontiff, according to St. Thomas, is guided by the infallible influence of the Holy Ghost in an especial way when canonizing saints.”
Will you tell me it doesn't matter what "Tom" or "Bob" (God forgive me, but it is necessary to show the consequences Fr. Pfeiffer's position leads to) thought, because, after all, St. Thomas or St. Robert may not be Saints? Do you see how problematic it is to say the Church has never held canonizations to be infallible?