Promised Mockup (I’m not dead set on this, while I don’t like the indent in the typical Clipping Mask, I think the mockups I made make the relationship a bit too much hidden for my taste…):
Also not a mockup, but shows the additional advantage of using Inherit Alpha; apparently in CSP you can’t “fold” the clipping mask? Though it does depend on implementation, we should be able to fix it even if we do implement CM.
