This may be late, but have you tried placing a multiply between the subtract and texture Coordinate? you will place the number you want in to be tiled by into the other node.
Ctrl + click converts the selection additive. Crtl + Shift + click converts the selection subtractively. If that doesn't make sense, just try them both and you'll see.
I might subtract the panties, they are the only thing (other than the make-believe armor and whatnot) that is not period based or that relevant, I was just getting cought up in details
This is because it will redistribute the subtracted weight among the other bones, usually in ways you don't want. It's better to paint positive weights to the intended bone and have it steal the weight it needs.
Is there anyway to edit the color selection map, I need to add some faces / geometry to the mask and subtract others but I cannot figure out how to edit the map