Okay so I am clawing my way through the channels palette/masks to try to get somewhere...I have gotten really close to understanding the craziness that is masks in Affinity. My question is, when you right-click the mask once it gets generated on the layers panel, there is the option to edit mask. About the only thing I can do inside the mask is paint on with brushes to effectively manipulate the mask. But I cannot figure out how to apply an adjustment here. I felt like I had solved the riddle of the Mask! But I didn't. sigh