In case you don't know, every time a gate launches, its stratum column in the arcade is filled with nothing but ?s except for one stratum which houses the boss levels that gate carries.
So, without the power of minerals in the Clockworks, what levels are there to create? I want to see (or at least know) what happens when a gate launches with a stratum missing a theme (as in it has the ? on it).
If a stratum is missing a theme, I think the stratum is either random or just pure normal.