That's all fine and dandy but Trent doesn't explain any of this. So Ott's explanation is purely speculative.
What Trent definitely teaches is that there is
something called "the desire for [the bath of regeneration]" that confers "justification" on the soul having such a "desire." This is the concept of BoD within the context of the docuмents from the Council of Trent. That there is
such a thing as BoD and that it deals with "justification" is part of the infallible Ordinary and Universal Magisterium.
You are correct that Trent does not discuss the all the details of BoD at length. So,
the precise details surrounding BoD are in the realm of "theological opinion." There is room for discussion about those details within limits.
But there is no room for discussion about whether BoD
per se is orthodox or heretical. BoD, understood at least to the extent described in the Trent "Decree on Justification," is orthodox. To claim that BoD, as Trent uses the phrase, is "heretical" would be to deny the authority of the Council of Trent.
And to say that "Ott's explanation is purely speculative" is baseless. In fact, it is the "common opinion" of Church theologians, which is why Ott included it in his textbook anyway. The "purely speculative" opinions on BoD are from those, with no formal theological training or authority, who refuse to accept the "common opinion" of the Church theologians prior to VII.