What features would you like to see in Pixelmator Pro?
Is there a blend tool? i would a bend tool to blend two "sides" of a pen drag and blend them together. So a blend along a black and white region would create a gray area. Additionally, if the pen wandered towards the white, the gray would be lighter and if the pen wandered toward the black side the gray would be darker.
For instance, I fixing a blemish. Repair does a pretty good job but still in places, the difference in color is a little to stark, too high of a contrast, for my liking. What I'm looking for is a brush the will reduce/eliminate that contrast line, making the contrast line must less noticeable. Smidge kind of serves my purpose but it messes too much with the detail. I guess I am looking a smudge that would alter the color of the pixels but not the detail.
If you're looking to brighten or darken certain areas of an image, you should be able to do so using the Lighten and Darken tools. You can learn how to lighten a specific area in an image here http://help.pixelmator.com/pixelmator-pro/1.4/#737, and how to darken it here http://help.pixelmator.com/pixelmator-pro/1.4/#738.