Okay, so the pope can exercise his power as he wishes whenever he wants. He reigns supreme in the Church. Can he therefore never make a mistake? Is every official act of the pope infallible? Can it never be overturned by a future pope? BTW, overturning Quo Primum is precisely what Paul VI would seem to have tried to do with the publication of the Novus Ordo sacramentary. So he must have been in favor of overturning previous popes' actions, even when they are extremely serious matter and use words such as "always" "forever" and "in perpetuity."
The so-called excommunication of Fr. Feeney was politically motivated and did not serve the good of the Church, in my opinion. It served to pave the way for Vatican II and the attempted destruction of the Mass and all of apostolic tradition. It made the road to perdition wider and easier for many Catholics worldwide. It was a key element of diabolical disorientation as shown by the overnight loss of popularity that Fr. Feeney suffered. I know people who were in elementary school classrooms when long term projects involving Fr. Feeney's name, picture, or writings were stopped cold one day, and his very name became a forbidden word in the school, all in a moment of time. Famous one day and vilified the next.
Bishop Fulton J. Sheen had a renown TV show in those days, and when he had to go out of town, he said that there was exactly one priest in the entire United States that he would trust to substitute for him hosting his show in his absence: Fr. Leonard Feeney. Years later, when Sheen had gradually slipped into the modernist net of updating things, he tried to renew his orthodoxy and he was shut down in one fell swoop by the same bureaucrats that did Fr. Feeney in previously. A man met Sheen soon thereafter on a public transit and Sheen told him he regretted ever having complied with the changes, they didn't feel right at the time, but it was a turbulent time. Now, trying to recover what was lost is nearly impossible for one man. He died soon after that meeting, a forgotten mainstay of tradition, swept aside like yesterday's rubbish.
I'm not going to explain excommunications to you. St. Athanasius was excommunicated several times, and today he's the saint and the men who issued his reprimands are long forgotten, some even "condemned" heretics.
You can keep trying to make excuses for such things as "baptism of desire," but to what purpose, so you can turn away well-meaning people like Kolokotronis who scoff at the silliness of the Roman Catholics sqabbling over things laymen are not equipped to discuss? Baptism of desire is not a dogma. Nobody is going to be excommunicated for denying it, and I suspect nobody has been. If that had been the basis of Feeney's "excommunication," in order for it to be "lifted" later, the puppets of the law would have required more than Fr's recitation of the Athanasian Creed to do so. The basis was his refusal to stop saying that there is no salvation outside the Church, plain and simple. Interestingly, when it was "lifted" the Creed he recited contains EENS at the beginning and at the end. It's in there twice. So, Fr. Feeney was "excommunicated" for saying there's no salvation outside the Church, and then the "excommunication" was lifted by saying the same thing twice in one setting. Hmm. Sounds perfectly just and logical to me!
NOT!
The damage done to missionary work by people presuming that they don't need baptism to be saved because all they really need is the "desire" for it, is far worse than simply sticking to the literal meaning of Scripture. The Latin text of Trent uses the word "in voto" which poorly translated can be "of desire," but a better word is "in vow." So it's not exactly the desire for baptism but the firm purpose of intention to receive it at the proper time. Big difference. But the latter does not serve the liberal, progressivist and diabolically disorientated agenda, does it? Perhaps you think it does.