You were right, Vidi -- but I was able to write a python routine which does automatically blur the auto weight
Any chance you would like to share that python script? Is it something that could be used by others? Sounds like a useful script.
the vest and shirt are part of a single mesh, so no chance to separate
I am not sure if this is the case in your particular instance but I have found that some 3rd party content is made from multiple mesh pieces that then then joined into one single mesh. While such a mesh appears as one mesh in software (like Blender) the different parts of the mesh are not actually stitched together and can cause odd effects especially when resizing or auto fitting. For example, when conform is used on such meshes the seams where the pieces of meshes are not stitched together can reduce/increase individually causing gaps to appear.
I will confess that in some quick content I am guilty of such atrocity myself...for example, my freebie Mrs Clause outfit (provided as a x-mas freebie) added a faux-fur trim to the end of a skirt. Since I already had a skirt, I just added a second mesh containing the trim and joined the meshes together. To save time, I didn't actually merge the two meshes to use common vertex points and thus while the meshes appeared as one mesh, they were still made up of two parts (the skirt and the trim). This is why, if someone turned on physics for the skirt, the trim fell right off (because there was nothing joining the two mesh pieces even though they were one mesh). I've even written myself a little app that stitches mesh parts together for cases where working on separate mesh pieces is desirable but I then want the whole thing to not fall apart.
"We often compare ourselves to the U.S. and often they come out the best, but they only have the right to bear arms while we have the right to bare breasts"
Bowser and Blue, Busting The Breast