Tried googling this but to no avail. Where does the gun clip go in jet mode? Especially with battle armour on. I have no idea
Due to the conflict with the armor, the gun clip cannot be used if the arm armor is also used. I think this goes for all 3 modes, not just jet mode.
since it's a a stolen OG Macross VF-1 design. The gun clip was always only meant to be used on the arms not the armor. because if it clipped onto the armor, (which even in the show it never ever did) the back landing gears would not be able to touch the ground. (simple engineering logic)