Well I'll give my opinion on the matter. If I get anything wrong, just say, because I'm not an expert in physics and ES cosmology is really weird. Bear in mind that there are lots of other views.
Even if we did not accept the 1-B feat, which I firmly disagree using at the moment unless we get more evidence in later games, we still have the following material which would justify a decent upgrade to at least a few cosmic ES profiles:
1.
Aedra have five dimensional feats, and they collectively created a five dimensional word of god 'multiverse' called Mundus. Refer to the official TESO story introduction:
"Nirn has come unmoored from the fabric of the multiverse"
https://www.imperial-library.info/content/introduction-lore-elder-scrolls-online
We already know Mundus has parallel four dimensional timelines in any case, from the Daggerfall ending, the mention of 'Adjacent Planes' and gods moving at 'strange angles' to escape Kalpas. I have found no evidence challenging the idea that it is a multiverse, but it is unclear what size it is (i.e. might not be infinite, I don't know how this changes things).
Oblivion is infinitely larger than Mundus, rendering each Daedric realm a similar multiverse of unknown size. Oblivion is an infinite six dimensional multiverse in this regard; is confirmed to contain an infinite count of realms by the lore writers. The fact that there are "sub" realms in Daedric realms implies parallel planes similar to Mundus.
Daedra can travel between each other's realms (happens plenty of times throughout the games) and according to a Demiprince (low tier Daedric prince), have the power to shatter each other's realms in direct combat:
"Then there are what we call the 'sundered realms,' pocket realities that were shattered by interplanar war or Princely expungement."
https://www.imperial-library.info/content/lord-fa-nuit-hen-and-tutor-riparius-answer-your-questions
This presumably showing that they exist on a six-dimensional level at least, and they can exist freely of realms if they want to. Daedra are also said to be 'hyperagonal' two times, and the word hyperagonal is used a further two times throughout ES. In the book, Limimal Bridges, the term is outright stated to entail extra dimensional, and in context it is very obvious that it is referring to higher dimensions. The term 'hyperagonal' has also been used in real articles, but it's very unheard of. I doubt it has an acknowledged definition, but even though I have no doubt ES writers made it up, it is still significant in context and in my opinion very unreasonable to deny. None the less, it implies that the spatial form of a Daedra is at least four dimensional, backing up aforementioned ideas.
Hyperagonal is also used two times in context where it implies extra dimensional:
"You think that, because you perceive a superficial resemblance between the outward appearance of the Nightmare Courser and the Hell Hound, that they must share a 'relationship.' Ever the mortal mind defends itself against the reality of what it cannot comprehend by the pathetic imposition of familiar patterns on entities of inconvenient hyperagonal morphology."
In this case, it is referring to the fact that mortals as three dimensional can only percieve a cross section of a lesser Daedra.
"Though other hyperagonal media may exist in theory, the only known transliminal artifact capable of sustained transpontine circumpenetration is the Sigil stone. A sigil stone is a specimen of pre-Mythic quasi-crystalline morpholith that has been transformed into an extra-dimensional artifact through the arcane inscription of a daedric sigil. Though some common morpholiths like soul gems may be found in nature, the exotic morpoliths used to make sigil stones occur only in pocket voids of Oblivion, and cannot be prospected or harvested without daedric assistance."
Here, even if we assume the term 'hyperagonal' is meaningless, it still states that Daedra can turn things into extra dimensional artefacts. Taking my prior view that major Daedric planes are five dimensional, a hyperagonal Sigil Stone could make sense in its use, in that it could allow a three dimensional being to point themselves at one of these cross section universes within a Daedric realm and travel there. Sigil Stones are also used to empower portals between Oblivion and Mundus, if that holds any significance.
Aetherius is furthermore infinitely larger than Oblivion, according to the 'Cosmology' book, and must be logically higher dimensional in order to not be part of Oblivion, which contains 'all possibility' (likely within a six dimensional context):
"Your problem, mortal, is exemplified by your words, 'share a common origin in the planes of Oblivion.' There is nothing 'common' about, between, or across the planes of Oblivion—they are the very definition of change and variation, manifesting all possibilities, and validating all understanding and misunderstanding. You seek similarities where there are only differences, a classification of chaos."
http://en.uesp.net/wiki/Lore:Lyranth_the_Foolkiller_Answers_Your_Questions
The Magna Ge reside in Aetherius, but they have no seven dimensional feats. All et'Ada originated in Aetherius. What this should apply to is Anuiel, Sithis and all other superceding entities, putting them at mid 1-C (seven dimensional or higher). Daedric princes should also receive a low 1-C rating for being six dimensional, or High 2-A for being five dimensional, depending on what you accept here?
2.
Mundus may have more than one temporal dimension according to two sources, but I do not take this too seriously, unless perhaps we get more information on it in the later games. This should extend to AKA(tosh) and potentially his aspects thereof.
"You look to your left, you see one way. You look to your right, you see another. But neither is any harder than the opposite. But the Elder Scrolls... they look left and right in the stream of time. The future and past are as one: Sometimes they even look up. What do they see then? What if they dive in?"
"It would take a month to explain to you how that very question doesn't even make sense. The Scrolls exist here, with us, but also beyond and beneath. Before and after."
Last time these were mentioned in a discussion, the result was inconclusive.
3.
There are many different ideas and I think unless we set up a profile system which lists all likely/potential tiers of ES gods, we're going to keep wasting the moderators' time calling for constant upgrades and downgrades, because there will always be people who disagree. ES lore and cosmology is incredibly complicated and open to many different views. Throw in the metaphysics and it gets even more complicated. Throw in what is canon and non-canon and it then gets even further more complicated. There is no simple answer, and I doubt the mods want to waste their time setting this up either. But I've given my views on the subject.
