Well I just learned something new and it makes sense. in a way. I always used an iron, tacked down the ribs and did most of my shrinking with an iron and pretty much only used the gun for open spaces that the iron couldn't reach . I would like to hear more as to why using my method is different and adds less torsional integrity. Of course I'm probably wrong, but I'm thinking that tacking down the perimeters and not distributing the load , you would be using less of a "point to point" contact area increasing more wing warpage as in increasing the bending moment created. Sort of like torquing down the head bolts of a cars engine head.