Contradictions are part of Steampunck lore like for example, nothing exists in Sharnoth, but everything also exists ie it's literal nothingness, just a dark realm, but it also has the shape of buildings....
Their unchanging nature and being type 1 concepts aren't really stated to be intertwined.
You can infer it maybe, it's stated that Sharnoth and thus M/Edison is unchanging, but at the same time Sharnoth is a realm that is beyond time, space and causality.
M being Sharnoth itself, and M being conceptual, you can say Sharnoth is conceptual.