Right. This goes back to the fact that until the Jesuit innovators came along around the year 1600, no Catholic ever believed or taught that salvation was possible without explicit knowledge of and belief in Jesus Christ and the Holy Trinity. Now, if I were living in the year 1400, I would rightly classify that unanimity among the Church Fathers and of the entire Ecclesia Credens as an infallible teaching of the Ordinary Universal Magisterium. One might even call the Athanasian Creed an expression of the solemn Magisterium as it had the approbation of multiple popes. But then one day someone wakes up in the year 1600 and it's no longer infallible and certain because one guy decided to question it out of the blue? That's nonsense. Otherwise, one would have to claim that something taught infallibly as a matter of faith can over time cease to be an infallible matter of faith.
Dante did. But he's definitely not of enough weight to challenge the consensus on his own. Justin Martyr thought Socrates, and those pagans who lived in accordance with reason before the coming of Christ, would be saved, but I don't know for sure if he extended that out to pagans who hadn't heard of Christ AFTER Christ came. At the least it seems reasonable to me that his reasoning could be extended in that way, but I need to look at First Apology again (I'm gonna start a thread soon on this particular section of First Apology, as that seems worth its own separate discussion. Augustine does say that some Donatists shouldn't be considered heretics. I realize Donatists believed in the Holy Trinity, so strictly speaking they don't conflict with your argument, however, Augustine's words there do present problems for *other* aspects of your interpretation of EENS (for instance, as far as I understand, you and Pax wouldn't believe that anyone who's visibly associated with Protestantism or Eastern Orthodoxy can be saved either. While a separate issue to "virtuous pagans", it still deserves discussion.)
I'd need to do more research. I realize Cyprian, from as far as I can tell, was an absolute hardliner here, but Cyprian =/= everyone. It might be true that nobody (besides Dante who isn't canonized) believed that virtuous pagans living *after* the coming of Christ could possibly be saved, and if that is indeed the consensus than I submit to it (I'll also note that this doesn't particularly bother me, I always believed this as a Protestant, and like, God knows better than me anyways) but I'd just want to ensure that that's really the case rather than just assuming.