As for your denunciation of "extreme" Feeneyites, the greatest theological problem I have is that BoD theory does not account for what the character of the Sacrament does. Church Fathers referred to it as as a seal, a glory, and a crowning, all of which were synonymous with elevation to the supernatural state in the Kingdom. If you look at even modern theologians, they list the two effects of the Sacrament, forgiveness of sin and imprinting of the character of Baptism. So, what does this character do? It serves merely as a non-repeatability marker for the Sacrament? Nonsense. That's to bankrupt the character of its true ontological significance. By nature human beings lack the faculties to see God as He is, as that's a capacity beyond our nature, and it's precisely the character of Baptism that supplies this supernatural faculty, and it's also what marks us in the image an likeness of God's Son, so that we become members of the Holy Trinity by adoption, entering into the life of the Holy Trinity, into the Kingdom. BoDers claim that St. Ambrose promoted BoD in his oration for Valentinian, and even St. Benedict Center failed on this one, asserting that this apperas to be a contradiction of when St. Ambrose wrote elsewhere in "De Sacramentis" that even the best catechumens couldn't enter the Kingdom without the actual reception of Baptism. But if you read beyond the single sentence quoted out of context, St. Ambrose explains his meaning. He hopes that Valentinian could approach a state that similar to that of unbaptized martyrs, whom he characterizes as "washed but not crowned". That speaks to the TWO effects of the Sacrament of Baptism, the washing (forgiveness of sins), and the crowning (the character). So, what is the status of a washed but not crowned? Sounds to me like ... the state that infants who die without Baptism are in, with no guilt of sin imputed to them (justification) but no entry into the Kingdom (salvation).
That distinction between the natural and the supernatural aspects of eternity was first cracked open by St. Thomas (after Abelard, who was anti-BoD first challenged St. Augustine's position on the issue), where he articulated precisely how the reason unbaptized infannts do not suffer is because what they lost is so far above their nature that they don't know what they're missing and therefore don't experience loss, since loss and the suffering due to it has to do with the privation of a due good, a lack of the perfection of the creature, and elevation to the supernatural state is not a privation of nature.
Once people figure this out, it cracks open everything, makes sense of the character of Baptism, truly expresses the effect of the character of the Sacrament, etc.