I'll start. Despite Cushingite lies, we have exactly ONE Church Father, purportedly a second, who opined in favor of Baptism of Desire. Meanwhile, we have about half a dozen who explicitly REJECTED this notion. In fact, even in the case of that one Church Father, St. Augustine, he merely floated the notion as a speculative opinion in his early days of being a Catholic, but by the end of his life had completely rejected it (after having battled the Pelagians and Donatists), and some of the strongest anti-BoD statements in existence come from the pen of St. Augustine. Meanwhile, the meaning of St. Ambrose's funeral oration for Valentinian is ambiguous at best, and elsewhere he too reject the possibility of even sincere catechumens being saved if they die before Baptism.
Now, even when St. Augustine floated the opinion, he made it clear that it wasn't some Traditional teaching received from the Apostles. He states that he had gone back and forth on the question and that in the end, it "seemed" to him that it was possible. This was no revealed teaching by any means.
Subsequent to St. Augustine, we have a couple of explicit rejections of BoD, and then complete silence on the matter until the Augustinian revival of the early scholastic era (1100s). It was being hotly debated between two of the pre-scholastics, Hugh of St. Victor (pro) and Abelard (con). Peter Lombard wrote to St. Bernard to ask for his opinion, to help resolve the debate. St. Bernard replied very weakly, "well, I'd rather be wrong with Augustine than right on my own." No other theological reasons were given. Peter Lombard went with this. He in turn influenced the scholastics with his Sentences. St. Thomas Aquinas adopted the opinion, and of course after him it went viral. Now, little did St. Bernard and St. Thomas know ... but St. Augustine had violently rejected BoD in his later works, but those were not available to them at the time. Had they known, they would undoubtedly not have gone this route. By the way, in the early pre-scholastic period, there was a revival of St. Augustine, and such devotion to him that the Church felt the need to condemn the proposition that it was acceptable to prefer an opinion of Augustine over a Church teaching.
Now, from the Church Fathers all the way through St. Robert Bellarmine, this consideration of BoD was made only in the context of a catechumen. St. Robert Bellarmine's scholastic question, for instance, was, "whether a catechumen who died before Baptism can be saved". St. Robert clearly limited this to the context of the catechumen and only tentatively landed in favor of BoD. And why? It's because, he said, the contrary opinion "would seem too harsh". In other words, for non-theological / emotional reasons. Of course, this caused problems for him, since in his ecclesiology he explicitly stated that catechumens were outside the Church since they had not received the Sacraments.
Here are the origins of this opinion. People saw that every once in a while, a very pious and devout catechumen would die before Baptism. At the same time, some "scoundrel", as St. Augustine put it, snatched salvation on his deathbed after living a sinful life. So there was emotionally-driven speculation as a result ... not theology. But St. Augustine eventually laid aside the emotion and followed theology, basically saying that to question God's justice and mercy leads to a "vortex of confusion" and we cannot say that God is powerless to bring the Sacrament to His elect. Other Fathers rejected BoD on the same grounds, realizing that the opinion was rooted in a presumption of people attempting to determine what would and what would not be "fair" for God to do. Indeed, they realized, this opens up a HUGE can of worms. There are lots of things that happen which to human minds APPEAR to be "unfair". How many people lose their faith after a tragedy, questioning how a merciful God could allow such a thing? That thinking is precisely what's behind BoD speculation ... and they knew it ... and they rejected it.
Fast forward to the post-Renaissance period. Subjectivism comes onto the scene, bringing with it a neo-Pelagianism. Of course in that theological climate they would find BoD appealing. So the opinion became more and more widespread. This theological rot is the VERY SAME as what's behind all of Vatican II. So we have Johnny here denouncing Vatican II as heresy while promoting implicit BoD. Little does the dunderhead realize, that implicit inclusion in the Church is behind all the Vatican II errors, the new ecclesiology. Religious Liberty is merely taking the subjectivism to its logical conclusions.
Not to mention Johnny's contradiction that we must accept BoD because it was held by the vast majority of theologians right before Vatican II, but we must reject the opinion of those same theologians that there's nothing wrong with Vatican II. These same theologians all embraced Vatican II and promoted it as Catholic teaching. But it's OK to reject that, but not OK to reject the opinions they held just before Vatican II. And the absurdity of this is mind-boggling. But that's what happens when someone is of bad will.