It's a really thought through system and I am happy there's a sample kit to try out before buying the full kit!
Although, I am having a trouble with the joints that hold the walls and pillars together. They seem to be wider for me than the edges on the walls and the pillars, and don't hold those as tightly as the fixations (3x3-floor-fixed or grfg-2) do. I tried printing them horizontally with the supports and vertically, both with the same result... Although the vertical ones hold just a bit better in the place of the elephant foot.
Any tips how to fix that?