(Psst, normal members can't ping notify staff.)
Anyway for this question there's a couple problems.
The initial statement for Solaris is that he's "Super-dimensional" which people like to extrapolate into saying it transcends all dimensions, but..
Let me establish a difference between an order and system really quick as well. When we use a term like Cho jigen (super dimensional) it can translate to “next order of dimensions”. Why is the word order here emphasized? Because this is where scaling gets prevalent to more complex issues and foreign concepts. Let’s take a system of dimensions, for example 22. There are 22 dimensions in this system, and are identifiable with the meaning of a cardinal number. For this system, these 22 cardinals are contained within an ordinal number or ω. A ω though despite having higher ordinals above that first infinite one, are still denoted by the same cardinality N0 (aleph null) so you can be above that first ordinal (order) that defines {1,2,3,…,21} But you’d still fall under the ordinal (order) that defines {1,2,3…..,22} .
[That's at least my understanding of it, someone can feel free to correct me on a lot, tl;dr is "Next order" is just a fancy semantic way of saying higher dimension]
With that in mind, if solaris's being had represented transcending not only the order of higher dimensions but the entire framework in an "inaccessible" manner, that could possibly be low 1-A. However, Sonic has never shown such foreign complexities, and never will as I'm the anti-thesis of sonic being outerversal.