I would find it very useful when adjusting Brightness [Luminance] if the Histogram dialog had a grid similar to that of the RGB Curve dialog...
Perhaps better yet, in order to increase the viewable image work space for single monitor setups, that the combined histogram distribution [R,G,B, C, M, Y, Luminance] displays in the background of the RGB Curves dialog... ...and when switched for an individual R or G or B curve adjustment, that particular channel histogram is displayed... ...eliminating a separate dialog for histogram distributions.
Thank you for the consideration... ...den...