Does the ROZ layer use the same flags as the normal tilemap layers? If so, are they disabling the wrap scroll enable flag when the images are rotated in?
I don't remember anything about the mode 7 settings on the SNES; but could the A'Can have based their ROZ layer on the SNES'? Especially since the Gameboy Advance was pretty much considered a handheld SNES (with a better CPU).