So, if the Diana Mini can shoot 72 half-frame pictures on a 36 exposure roll, or 36 square exposures, does the film advance advance the film on 24×36 boundaries?

Two half-frame shots should print out on a 4×6 print with a fine line between them, and normal spacing between 2 half-frame shots. I’m assuming the square frame would advance the same distance as a 24×36 image?

If you shoot one half-frame shot, then switch to square, then shoot half-frame again, how would the negative look? And, would your photo processing lab try and follow along, or just print evenly-spaced 24×36 prints regardless of what’s on the neg?