Uhm, rethinking of that, Ingrid may have arguments in favor of a single tier.
She does draw all her powers from sources such as the sun and the "cosmo" (which she explains being the extrauniversal realm) and she is also a catalyst for Psycho Power, on top of being possibly the maximum espert in regards to ki (such as the reveal that ki is an energy drawn from other dimensions).
Her physical body is also a byproduct of said energies, so she may very well be the most "UES character" of the franchise.
I'd say it's different from Gill, because the source of his powers is vague at best, and not all characters draw elemental powers from ki.
That said, if we choose the path of the physical-hax split, I agree with upscaling from Akuma's meteor feat.
I also disagree with splitting her in keys judging on Alpha 3 and her 15 minutes statement. Even there, she takes 15 minutes to react Bison after defeating Ryu, having a little banter, stomping him, chasing him to the Psycho Drive and ultimately killing him, all the while showcasing little hurry. So, I wouldn't take it as indication of her power being too limited to finish things quicker. Also, while she experiences time, I'm not sure it really affects her. She states to not age, and that her various projections have varying ages, from millennia to less than a century.