Thanks by the info Lewis Luminos, but not, the question is not that. Is not for my own use.
I am creator of feet and sell with standards sizes, these feet need 3 values of shape to be matched.
Some customers have experience editing shapes, but other people not. Also the problem with the languages in the viewer, some people dont have the editor shape in english, then is very difficult to set these values without help, or as I say "with headaches".
My intention is to make the life in Secondlife more easy and happy for customers.
Technically only Linden Labs can make the solution that I say. And really the solution technical is there, in the same way as we know "wear a base for shoes", that are some values of sliders applied partially to the shape.
Can be a file in text format with the only needed values that we put on some "new button" in the editor of shape, and making a new item wearable that set theses values when weared.
It is a idea for Linden Labs if like it, I think need programming, but a bit only.
The idea seems simple, but we can reflection about all advantages that we, the creators, in SL can get. It is a workaround to the problems of fitting mesh. Can coexist with fitting mesh, and too in some ways not to be the need to fitted mesh.
Every creator could create various sizes of theirs creations and various "partial shape changer" (items).The customer wear a pair of feet of size S and wear the "partial shape changer S".