What makes you assume that human ontology is maximal? Kant surely did not. He assumed we are bound by the forms of intuition to almost always merely approximate reality, whereas a divine being would be able to know a deeper reality more directly. Presumably a semi-divine being would see some intermediate approximation much better than what we might attain.
I would claim that we are even more restricted by our biology than he imagined. Our physics is starting to show us a reality where we have a very hard time going. They are basically the same places Kant imagined we would find walls.
- We cannot avoid thinking sequentially despite that our own thought processes are not sequential but parallel, so we are failing to even leverage what we have been given.
- We cannot dispel the illusion of space, despite experimental evidence it ultimately fails us. Arguments around space at the Planck length are bizarre, because they have to use continuous curves, but the whole idea is that space is discontinuous there.
- We don't seem to be able to dispel the notion of quantity and retain abstraction, so we have a hard time truly visualizing things we know are real, like fractional particle spin.
- We have a very hard time evading the limitations of quantification or negation, even though we can see that together they lead to logical contradictions (like Russel's paradox) -- heading down that path is just too alien, and we construct a fake playground where it is safe to talk normally, instead.
Surely we can imagine creatures that would be less hobbled by their nature. So our limitations should not be assumed to place a global limit on intelligence, since we know there are limits we are unlikely to transcend without a considerable evolutionary modification of our own capacity for visualization, while at the same time, we have good clues as to how much further specific improvements might take us.
A more meaningful analogy for many of us would be:
dog : (proximal) experience :: human : X :: ideal intellect : Reality
Where establishing X is something hard to identify, but definitely important.