"Therefore, no one will be saved who, knowing the Church to have been divinely established by Christ, nevertheless refuses to submit to the Church or withholds obedience from the Roman Pontiff, the Vicar of Christ on earth."
Amen. Btw, just as it's indubitably clear to anyone who reads the relevant docuмents of that time period that Pope Pius XII was well aware of everything the Holy Office did in his name and approved their doctrine (with 3 AAS docuмents no less), it clearly follows that Pius XII is a heretic if what the Church under him deemed to be "very harmful both to those within and outside the Church" is in fact somehow the true doctrine of the Church. But it doesn't even end there. Leo XIII approved the Baltimore Catechism teaching both bod and EENS in the same Catholic sense taught by Pius XII. Thus, if as Feeneyites erroneously hold, that sense "contradicts the dogma" (being like Calvinists and Jansenists, misunderstanding true Catholic EENS/predestination), Leo XII would be a heretic too.
There's something called reductio ad absurdum. It's used for proofs in mathematics and logic. When you reach an absurd conclusion, like that 99% of traditional clergy, traditional popes etc are heretics or teaching heretical doctrine, you stop and consider the possibility you yourself are gravely mistaken. That's what Feeneyites should do here. Instead, they stubbornly refuse to admit they are at war with at least the past 150 years of Roman Pontiffs themselves. Leo XIII would have excommunicated Feeneyites just like Pius XII did. Either (1) those 150 years of Popes were all heretics, or (2) the Feeneyites are wrong about their heretical, warped perversion of EENS, which is totally different from the true traditional Catholic doctrine of EENS. That makes it real simple for real Catholics.