personally, as easily made as solid trailing edges/flaps and ailerons are, I prefer to build them up from sheet stock as top and bottom skins with the wing rib between or a small wedge in between for flaps and ailerons. I've seen a few times where the thin tapered edge of a solid aileron or flap warps and I don't like the glued butt joint between rib and trailing edge when using a solid edge. it's just a weak spot waiting to fail. if you're going to cover that butt joint with partial sheeting, why not just eliminate it by running the rib down between the top and bottom partial sheeting.......so much stronger and lighter aft of the C/G.