A lot of photographers have different takes on this subject but generally I appreciate being asked before seeing one of my images re-retouched for a few reasons: 1) if it’s a black and white conversion, I probably don’t mind just doing it for you while still having I put in the finished image. 2) Photographers work off of monitors calibrated for color, contrast, and brightness accuracy. 3) Editing a JPEG that has already been edited and compressed... not good... like trying to recook a pasta dish with noodles and sauce that have been sitting in a fridge overnight. At the end of the day it’s not the end of the world but I appreciate being asked first. Am I missing anything?