(This is a working hypothesis. It also doesn’t change the fact that I see myself as a disciple of Dekonick, who IMO belongs in the tradition as much as John of St. Thomas or Cajetan.)
Dekoninck frequently drew attention to being as the most indefinite of concepts. Given that human knowledge moves from indefinite and general ideas to distinct concepts, we can reason to the idea that it begins with the most indefinite and general concept, which seems to be being. Taken in this sense, being is the upward terminus of the Porphyrian tree.
The argument is good as far as it goes, but it passes over the problem that while what is higher in the Porphyrian tree is what is less and less formal in things, “being” is what is most formal in the things. For Joe Smith, “animal” is less formal than “man”, but “being” is more formal than both, since it is an act to which all other acts are in potency. Again, while “animal” is just a vague, abstract way of grasping what is concretely a man or a platypus or a goat, “being” is not just this. This difficulty is not trivial: DeKoninck spent much of his life treating the division of the sciences, but he never treated the problem of being as formal to the science of metaphysics. In fact, many things he said about being were deprecatory and even dismissive, and his account of metaphysics (such as it was) tended towards seeing it as nothing but a terminus of natural philosophy- as though there was nothing more to metaphysics than a natural philosopher saying “Oh, I guess God exists”, and then falling into perpetual silence. This attitude was imparted to his students, of which I am of the second generation.
There are moments in the early Dekonick that escape this critique (his early lecture on the principle of contradiction is a brilliant example). But on the whole his teaching is characterized by overlooking some very significant things that St. Thomas says about being.