The rails on a Onewheel have delicate screw holes as they are made of aluminum. One stripped screw in the rail isn't the end of the world but I personally would not purchase the board unless I planned on replacing the rails or it is a board for a great deal. The rails are essentially the frame for the Onewheel. One less screw will compromise the water resistance at the very least if not the integrity of the board. Do not purchase a board with multiply stripped screws unless you have replacement rails.