Stone Alpha-izer
sublime tool
https://gumroad.com/l/KUdgc
Had a quick idea for Substance Painter. A .sbsar that converts any B&W mask to a mask with alpha for use in paint layers. Great for layering on scratches! Demonstration below.
With Stone Alpha-izer 
https://i.gyazo.com/88070e90a6b4cacc425b895adae5d0e7.mp4
Without Stone Alpha-izer 
https://i.gyazo.com/1278320fb93168a223a442a1a3fe3a8a.mp4
To use, import the .sbsar into Painter as a generator. When in "3" / projection mode, drag it into the input slot and then drag the desired alpha into the new input slot.
Only works with bitmaps, not built-in Painter generators.
@Allegorithmic if you know of a way to have it work properly with generators please let me know!