Noticed a possible bug: I have it set to only create buildings with one floor but it keeps making multi-story buildings instead, seems to ignore the parameter entirely. Would like a toggle to make sure there's no basement, as well.
I can't reproduce this. However, if you select one of the "stairs tags" (spiral, stairwell), an extra floor is spawned, because that staircase needs to lead somewhere.
I'll probably add a special tag in the future to prevent the basement from spawning.