Update V1.2 :
Maintain Stroke Script is for maintain Stroke Width of a shape layer even if the layer or the parents are scale.
It works with Kbar extension.
Select your shapes Layers which want to maintain stroke.
It's create a null with a slider to control the thickness of the stroke.
If you select another stroke after first use, the other stroke will refer to the Control_Stroke Slider.
v1.2: Working for all stroke in subgroup too.
v1.1: Working with one button.
ComingSoon: Creates multiples slider for différent thickness of Stroke.
Thanks to Dan Ebberts and Adam Plouff for the base of script