In at least one of the videos that showed excessively gappy side covers, the reviewer didn't seem to have the swingbar armature properly connected to the hip sockets or backplate, so the backplate wasn't fit as closely to the cockpit fuselage as it should have been. It's possible to make the same transformation error on both the Yamarcadia and DX valks, so it seemed like a pretty cut and dried case of mistransformation.