Mask Amount sliders

To further enhance the mask usefulness in addition to Invert and Copy [previously suggested]...
...would it be possible to use Black/White Amount sliders rather than perhaps the Invert switch where Mask white at 100% is the image area to be changed and Mask black at 0% is the protected image area?...
By reversing Mask white to 0% and Mask black to 100%, you have an Invert... ...but in addition, you have Amount control for partial changes in either the white or black or both masked image areas...
White/Black could be any color... just used here to represent protected and unprotected image areas for change.
...would it be possible to use Black/White Amount sliders rather than perhaps the Invert switch where Mask white at 100% is the image area to be changed and Mask black at 0% is the protected image area?...
By reversing Mask white to 0% and Mask black to 100%, you have an Invert... ...but in addition, you have Amount control for partial changes in either the white or black or both masked image areas...
White/Black could be any color... just used here to represent protected and unprotected image areas for change.