Hello, saw this post and thought I'd share. I shoot the R5 so not sure this will be exactly the same. When I am shooting in Manual with AUTO ISO all I have to do to set EXPOSURE COMPENSATION, is touch the Exposure Scale on my view screen (Usually with my thumb to be quick). It will immediately change to a yellow color with a box around it and enlarge the scale. (In normal exposure metering it is white box around the scale so this is a quick verification that it is in the Exposure Compensation mode - YELLOW). You can then dial in what compensation you are needing. It will remain there until you change it back to "0" as long as you are still in that same MODE of shooting, even if you turn your camera off and back on. Be sure to check the compensation in that MODE. I found this the easiest way to adjust compensation quickly while having an automated function active. I also DID NOT want to change one of my other buttons to compensation as I use both of them for BACK BUTTON FOCUS. (Yes, I know I can change one and keep one as Back-Button-Focus but...when I'm shooting in a "quick" situation, I found myself stalling to figure out which button my thumb hit, so, they both got set and the "stalling" situation is now avoided.) Hope this helps with the EOS R. I know your post is a year ago, but sometimes we still search for answers that might help in a different way and/or for others that have the same questions. Happy Clicking!
