Been thinking about this for a while.
You guys all know Doctor Strange mind-haxxing Umar being one of the Low 1-A mind-hax feats we use? Well, while the feat itself is fine, the potency...may not be.
According to DA RULES, hax is determined by the dimensionality of the target or its scope, not AP, and this includes mind-hax.
SO, we'd have to (in this case) look at the dimensionality of Umar, which should be the same as Dormammu, aka the Faltine Realm (which is at least 1 dimension above the Dark Dimension).
The Dark Dimension is at absolute minimum 5-D, via being a timeless higher dimension, and via Dormammu calling space and time "dirty". It is likely higher, as it still scales above the 6.29-D statement for the normal cluster of universes, should be comparable to Nightmare's 6-D dimension, and Dormammu indicated that he was multiple planes above the 4-D universe.
So the DD is at minimum 5-D, likely 6-7 dimensional. Consider the hax potency of Dormammu and Umar is repeatedly shown to scale to the Dark Dimension itself, that makes sense.
Thus, since Umar scales above this, that would make Doctor Strange's mind-hax feat 6-D to 8-D.
BUT, we still have Low 1-A mindhax, largely due to Xavier mind-battling the Phoenix Force, which is Low 1-A in Dimensionality (supported by Xavier mind-fighting it on the "Infinite Planes of Existence", so the mind-hax feat is minimum High 1-B, but is Low 1-A because the Phoenix has Low 1-A dimensionality.