Now, the thing regarding "If you were to shove the more concepts of higher time and space dimensions at the Overvoid, they would just get lost, engulfed, and forgotten in the Ultimate concept that is the Overvoid" is probably the crux of the matter. Thing is, conceptual erasure of space dimensions is also bound to NLF. Just because you can conceptually erase dimensions, does not imply that you can do so for any number of them. We have long since abandoned any idea of concepts inherently being above dimensions of any number and things like that.
Hence, the Overvoid being able to conceptually erase any dimensions put into it only matters to the extent as the verse has mentioned to have dimensions. There is little reason to assume that a theoretical space that might be "bigger" than the Overvoid, so big that it could enclose it, would get erased by it, no?