P: Better color control options for masked areas (i.e., color grading, color calibration)

I love the Color Grading tool - which is a global edit - to highlights, midtones, shadows, and global.  I often use this tool to get my whole image the right color feel.  It would be really useful if there were also an additional color grading tool for masked areas, such as when I wish to adjust masked skin tones.  The global Color Grading tool (and global Calibration tool) provides much better color control, for my uses, than the color options available in Masking ("color temp, tint, hue").