There's something wrong with the staircase buildwise, no amount of rotation, support, or placing temp pieces allows you to place a spiral staircase on top of another so the stairs continue upwards. You have to offset it, which takes up space and looks ugly.
I used these in the previous build, stacked one on top of the other to create a multiple-level spiral staircase.
This is no longer possible.
Doing some testing, it looks like these require a floor/foundation below them and another set of spiral stairs isn't satisfying this condition.
Adding column/s on the 'corners' of the cube that the stairs occupy isn't enough to satisfy the support requirement, either.