Can you at least admit that BOD is not predicated on the idea that it is impossible for God to work a miracle to baptize someone with water? If not can you supply the source that teaches the contrary?
But that's where the idea was originally hatched. BoB was first developed because people saw some catechumens getting martyred, whereas there were veritable scuмbuckets who got baptized on their deathbeds after living lives of sin. Then BoD came along for the same reasons. This was admitted even by St. Augustine, that the idea was founded upon people questioning whether this was "fair". There's no evidence that this was revealed or you would have all the Church Fathers unanimously teaching it. But against St. Augustine you can find about 4 or 5 Fathers who very forcefully reject BoD (some accept BoB but then reject BoD). St. Robert Bellarmine admits that the Church Fathers were divided on this issue.
That's why I question your statement that BoD has been the "constant teaching of the Church"; there's just no actual evidence for that.
There are two ways in which something can be said to be revealed.
1) directly revealed, as indicated by a unanimous consent of the Church Fathers (no such evidence exists)
2) implicitly and necessarily derived from other revealed dogmas (I have seen no syllogism which derives BoD from other revealed dogmas)
Consequently, I see no evidence for this to be
de fide. I see it as little more than a piece of speculative theology, based on various emotional reasons (as I outlined above), that the Church has allowed and tolerated and even endorsed (but never definitely taught or defined).
Yet I see also that BoD was extended gradually beyond catechumens to various heretics and schismatics, and then even to infidels and pagans. And it's this idea which has been exploited to lead to the modern V2 ecclesiology and to religious indifferentism.