I'd like to have an output mask that can be applies to individual slice (or polygon, or whatever)
Now there is only global output mask that masks everything below it, and you can't use it to cut some shape and place it over the rest of your output composition.
Input masks don't very well work for me in some situations because if you want to map some specific shape on what you are mapping on, masking input is anti-intuitive, you don't see what are you mapping out in relation to other slices.
Feather option would be nice too
Yuri