After wiring your quarter panels to #4 panels and galley flat, you will note that the fourth quarter panel corner is as yet free floating/unsupported. This means that if there is a twist in the quarter panel which is hard to see just eyeballing it, you don’t want this twist to be permanent when you fillet the quarter panel in in the next step. The galley flat does a poor job of controlling the angle at the free floating corner. The solution is to measure the #4 panel/quarterpanel angle on the teardrop floor ( whether or not you have assembled your floor at this point) with a bevel guage, then use the guage to set the corresponding angle on the quarter panel, using a temporary brace stick CA glued between the panel #4 floor corner at or near mold frame 5 and the unsupported corner. You will appreciate the advantage of having done this much later when you fit/ put your floor in, and again later when you fit/put in your transom.