The Questionable Plain is the start of the 12th class and contains Blancc. It is green and looks like an abstract. It also is contained by Bezkonceverse and the Blanccs are floating. It is also home to The fundamental superhuman, who lives in one of the Blanccs. It is full of triangles and those triangles are Blanccs.
Its questionability comes from its abstractness, in its pure form. The Questionable Plain is a very odd and largely unknown location where all of exsistance and its various states going above and below 0 are not permitted to exsist. Think of it as a big Inane. A VEEEERY big Inane. The only way to access the other Blanccs (The smallest triangle level) is through a very thin bridge between Blanccs only 1 universe wide and tall, which is also very delicate. It takes many years of careful Macroforming with small macroformers to make this place habitable outside the bridges. At all. Making a macroformer for this verse is even WORSE is you somehow get to multiple of them.