I just realised a neat little trick to make sure you have mid-grey where you want it, when adjusting exposure.
Enable mid-grey mask in color balance rgb before adjusting exposure.
Maybe, maybe not. That depends on if you have correctly set exposure in the first place (in DT, not the camera) and what you have done in the pixelpipe between exposure and color balance rgb. Tone eq, notably, can easily move mid-grey if you’re not careful.
What exactly is it you don’t understand?