The laser cut for the ailerons on the top surface is because of the laser cutter. The laser only cuts from one direction, so it's a cut through, a score, or a light mark. It's actually a happy accident as it extends the life of the ailerons. By cutting on the top surface, the foam is less apt to separate from the paper. Even on the V1, i put the 45 on the top, rather than the bottom. To make it last longer, put some hot glue on the hinge-line and squeegee it off. You can see this in many of the videos.