So, I built a base on top of the rock wall to the East. I first put down clay for a foundation along with walls, floors, and roof without a problem.
The first issue I noticed is that the floor is blended graphically into the clay instead of sitting on top, I would have expected it to appear above the clay without needing to use scaffolding.
The second, and bigger issue, is that any time I try to build an object (chest, lean-to, lamp, etc...) on top of the floor the blueprint is never shown despite it being in build mode. I have to cancel that build, go outside, and start the build pr