Siscoe, Xavier, what's next? Salza? Sammons? Tim Flanders? Anything to avoid addressing the issue. +ABL appealed to fruits many times, fruits show that an apostolate is the work of God and has had the blessing of God and is operating under the right principles. Our Lord Jesus Christ Himself told us to know a tree by its fruits, therefore we can.

"which clearly is against the law of Quo Primum"

Lol. Quo Primum does not say any other Mass can never be legitimate, otherwise all the Eastern rites are also illegitimate, as are also the more than 200 year old Western rites that Quo Primum allowed to continue to exist. The New Mass is valid but inferior. This is the classical Indult traditionalist position beautifully articulated by both +ABL himself (in the early days especially) and by Fr. Ripperger too. This position is compatible with the Church's indefectibility and is accepted by Rome. The opinion that the NOM is like a Black Mass is not, because that opinion denies the Church's indefectibility. Still, in the 1988 Protocol, which +ABL signed, all that was asked for is to confess that the New Mass is valid to reconcile with Rome. The FSSP signed the same protocol minus the provision for a Bishop.

Vatican II is non-infallible and can be respectfully question. But non-infallible Magisterium cannot be heretical. Not possible.

Is it just me or is anyone else starting to get a whiff of Xavier here?

Lol. Stubborn, yes I've read Quo Primum. Have you, carefully? Read this part:

"This new rite alone is to be used unless approval of the practice of saying Mass differently was given at the very time of the institution and confirmation of the church by Apostolic See at least 200 years ago, or unless there has prevailed a custom of a similar kind which has been continuously followed for a period of not less than 200 years, in which most cases We in no wise rescind their above-mentioned prerogative or custom. However, if this Missal, which we have seen fit to publish, be more agreeable to these latter, We grant them permission to celebrate Mass according to its rite, provided they have the consent of their bishop or prelate or of their whole Chapter, everything else to the contrary notwithstanding". https://www.papalencyclicals.net/pius05/p5quopri.htm

So Quo Primum itself grants various exceptions.

Also, Quo Primum, when established by His Holiness Pope St. Pius V, was binding on all Bishops and Priests to obey the Pope. But it does not bind all the Pope's Successors, who equally have the power of the keys. I do agree no Pope can ever ban the TLM though, as Bishop Athanasius has also said, anymore than he can ban the Apostles' Creed. We have the right to respectfully resist that.

Your opinion about the Magisterium is wrong and not even Fr. Wathen agreed with you on that if I recall right. Magisterium does not mean teachings. It means teaching office or teaching authority. If you knew Latin, you'd know this. All theologians know this and teaching you that, including all Pre-Vatican II theologians unanimously. But then you'd believe all of them are wrong ...