To follow up on that ... just study the dye curves on the published tech sheet. If you grossly overexposure you do indeed get more exposure on all three layers, but at the same time, force the
shadows down onto the lower part of the curve where's there's an overlap, hence contaminating one
dye with another. Once this happens, you're not going to clean it up. This is just basic sensitometry,
and was well known in prinicple to color photographers for a long time. But lots of things which were
once standard have now been forgotten because people think they can accomplish anything afterwards
with a few Fauxtoshop tweaks. That's simply not the case, any more than one can restore a clean primary hue to paint once you've intermixed two ingredients across the color wheel. Basic color theory.
Once you create dirt (or cowpie, or a complex neutral) you're not not going to easily fix it.