Playing devil's advocate but none of the V2 popes have been formerly declared heretics, per canon law process. At this point, most of their errors, though public, are not considered 'teachings' of the papacy but errors of their 'personal life'.
Related to this, name one error that is 'binding' on anyone, under pain of sin. V2 and the new mass are not binding as are none of the other anti-catholic verbiage being spewed from Rome. It doesn't change the fact that the errors are wrong, but as they are not binding, they are not from the official church, they only appear so. As Our Lady of LaSalette said: "The Church will be in eclipse".