Doesn't seem to address column/spindle parallelism. I would hate for a tool to move about in the X-Y plane as a function of Z-axis height. It seems to me that it's nearly useless to tram the head to the table if the quill moves differently if the height is adjusted differently (by adjusting the height of the head via the column vs. raising and lowering the column via the spindle).
IOW, the "nod" and tilt of the head should be aligned with the column before starting to tram the head with the table.
I can't be the first person who's worried about this with his X2. They've been around too long, with too many smart people, and the problem should have manifested itself if this is something other than a theoretical issue. Kind of like worrying about parallelism of the quill taper (resulting in runout of the tool inserted into the taper, although this article does seem to raise that point).
