Feathering mask borders / Jiggling issues


I’m experiencing an issue. I’m using a square mask to make a cool parallax perspective feature, but I’ve found that the mask’s borders are jiggling around and clipping with the actual tracking image because of tracking issues that we probably all got used to at this point (the constant jiggling). Is there any way to perhaps feather the mask borders, so they’re not pixel-perfect hard borders and thus the clipping/jiggling won’t be that noticable?