I agree with a lot of your points. A square mid is easier to get tight to the ground on uneven surfaces for sure. I find it easy to judge the angles for the hex (engineer by trade) and the golite tensioning straps work well to take up unevenness, albeit with some ground gap.
For me and Kath, the hex is great. I'm a giant who needs to sleep corner to corner, whereas Kath is a shorty, who can tuck in beside me in the space left. This leaves us lots of room for gear and cooking on the other side of the pole.
For a serious expedition, and minimal weight with two more even height people, I'm sure your square mid is more efficient.
Much respect for your craft and the quality of your work.