Anyway, regarding your proposal: For short, it's still running into the mother of the No Limits Fallacy, which is the Hasty Generalization Fallacy.
Like, a cut-off point was never the issue. We could have said it ends at "above all mathematics" as a cut-off point. However, as we decided in a thread not too long ago, we don't really do above all mathematics statements either. Because the existence of a cut-off point doesn't help, if it is a completely ridiculously large one, which nobody but some vs-debate nerds would ever even come up with.
It just is immensely speculative to take a statement of being above dimensions and extrapolate it to being above infinite infinite hierarchies of infinity and more without further evidence on that scale
Invoking the hasty generalization fallacy doesn't really mean anything here. The issue with hasty generalization is often that it involves making a broad conclusion based on a sample size that's statistically insignificant. Stuff like "I saw a Californian kill a person one time, therefore all Californians are murderers," revolving around cases where there are several underlying variables to take into account that can, and often do, make the claim an obviously untrue one, which is not the case here.
To illustrate this, I can cite the NLF's other mommy: The Proof by Example, the formal equivalent of hasty generalization, whose structure is as follows: "
I know that x, which is a member of group X, has the property P. Therefore, all other elements of X must have the property P." Phrasing my argument in this format, it would go more or less like: "
I know that 4-dimensional space, which is a member of the class of all dimensional space, is transcended by this character. Therefore, all other members of the class of dimensional spaces are also transcended by this character.."
What makes this argument ultimately not be subject to that fallacy is the lack of variables influencing the conclusion drawn from the premises. In the example above, for instance, saying that all Californians are murderers based on the fact you've seen a Californian kill someone one time is obviously wrong because groups of people are not a single unit with an homogeneous mindset that'd condition all of them into killers. Likewise, you could say "I saw three black swans by the lakeside the other day. Therefore most swans are black," and that'd be wrong for a similar reason: The fact you saw some black swans doesn't discredit the possibility that there are more white swans than black ones.
The trend you see here is that, in such cases, the members of the group you want to make a claim about are discrete entities that lie independent of each other. The existence of a black swan has no effect whatsoever on the existence of a white swan, and vice-versa, and likewise the existence of a Californian person who is a murderer has no effect on the existence of a Californian person who isn't. As such, what applies to the particular scenario doesn't necessarily extend to the general scenario. Your Hitler example, bizarre as it is, is the same thing (Though my lawyer has unfortunately advised me to make no further comment on it)
Mathematical concepts are not like this: We don't wave our hands around and conjure these things by magic, we establish primitive notions and instruments, and then work our way up, building larger and more complex things out of the foundation they provide. What this results in is a state of affairs where larger things depend on smaller, more basic ones, and are defined in terms of them. When we consider R⁵, all we're thinking about is the real number line multiplied by itself five times over (R x R x R x R x R), which is to say that 5-dimensional space is defined in terms of 1-dimensional space. To have 5 or 91 or 81,519 dimensions, we first need to define 1 dimension. This is a degree of uniformity and dependence between members of a group that is not present in other cases where a hasty generalization is being made, so, for all intents and purposes, when you transcend one dimension, you already transcended them all. One case already holds the basic ideas that also apply to all other cases.
This transcendence I speak of, of course, being on a fundamental level. This is an important distinction to make because when we talk about all these fancy terms like "transcendence" and "qualitative superiority," all we really mean is "This thing has uncountably infinitely more power than this other thing," which is really not superiority over the lesser thing in any fundamental sense. Compare a 3-D object that has length, height and breadth with a 2-D object that has only length and height. The 3-D object isn't "above" the dimensions of length and height, it's just infinitely larger than something that has only those dimensions and no third one, and were you to remove 2/3 of its dimensions you'd find it is now reduced to a 1-D object.
To that comes that it makes broad assumptions of the limits of dimensions in various cosmologies. In real life, the number of dimensions we have isn't decided purely by mathematics, but mostly by physics. If physics says we can have just 4 dimensions, then more don't and can't exist.
Similarly, in fictions, the limits of what number of dimensions do and can exist can be limited by their own internal rules of physics, mathematics, logic or supernatural forces. Assuming that no limiting factor on the possible dimensions exists, just because none is mentioned, is then again a NLF.
I think what I put in bold there is quite honestly the only good point you've made here, so I'll ask you to elaborate more on that. To my knowledge, physics never really goes "Anything past this specific number of dimensions can't exist," at most it's "There is no evidence for this many dimensions nor any real utility to positing them in our models." Moreover that paragraph also leaves out verses where reality and its structure is defined by something other than physics. What of verses where those are, indeed, decided by mathematics, for example?
Second paragraph: That mention of "supernatural forces" there is probably a bad example to list. If the number of possible dimensions is being actively suppressed by an in-verse force instead of somehow being just intrinsically low, then that's a feat for the force in question, and not something that helps you make your point. Assuming that a verse functions on wholly different principles of math, also, sounds really weird, given how the very system we'd use to tier it does operate on those very principles, so randomly positing that a given verse doesn't would create an odd incompatibility, not to mention it'd also give us precedent to ignore whatever directs us to ratings we happen to not like. Logic? Same thing.
Strictly speaking, I also never said that I am not assuming a limiting factor. The limiting factor, in this case, would be the indeterminate status of the validity of cardinals beyond vanilla ZFC. Is it a really high limit? Yeah, but it's a limit nevertheless. I guess you could feasibly say "Well, this same uncertainty applies to the Axiom of Infinity!", and that'd be a fair point were it not for the fact we already assume plenty of physical infinities exist as is. And ontop of that, any verse where infinite amounts of things exist would also be exempt.
Not to mention that, if a character is described as beyond dimensionality altogether, then that's not necessarily restricted only to dimensions that exist in the physical. If a verse has only 4 dimensions and then a structure encompassing it is described as exceeding dimensionality entirely, do you really think that, in-verse, that structure could be modelled as a 5-dimensional space? If so, why? And how wouldn't that just contradict the idea that it is supposed to be above dimensionality?
Not to mention that your desired cut-off point is so unknown, that most authors wouldn't even know it, making that interpretation of these statements most likely entirely against what was meant, and hence essentially purposeful misinterpretations for powerscaling purposes.
By that logic, most calculations and the like are "purposeful misinterpretations for powerscaling purposes," too. As is everything from Low 2-C and onwards (And really anything that gets remotely technical). Ultimately the intent of the author is entirely unknowable in 99% of cases and hinging ratings entirely on what you think they "most likely" knew is bad practice. It's completely irrelevant, bluntly speaking.
It's like taking a statement "He's so durable that literally nothing in this world can hurt him" and giving High 3-A durability for that, because that means that actual black holes shouldn't be able to do damage (except that our standards of evidence for extraordinary Tiers like High 1-A should be 10x higher than for High 3-A). It's taking a very unspecific statement and interpreting it to include a very specific extraordinary case.
Firstly I ask that you stop acting as if higher tiers should be inherently harder to reach than lower ones solely for the sake of it. In principle they should only be "harder" to get to because of the large scope of the things involved in their definitions and the specificity of terms that comes with that, not because of us going out of our way to artificially kneecap statements for the sake of conforming to some utterly arbitrary notion of "This tier should be super duper hard to get!!". Reminder that 1-A, High 1-A and 0 aren't even terribly difficult to get as is. All you need to do is mention a big cardinal and then have something somehow scale to it. That easy.
Secondly, that hypothetical statement has a lot of variables that'd need scrutiny. What does "world" mean, in this context? Because if world refers to a planet, then it can easily be Tier 7. High 3-A as a possible rating also assumes that gravitational singularities exist (We don't actually know if they are things that are somewhere out there or just a result of the formalism of general relativity going out of whack due to the conditions past the event horizon). List goes on.
