I cannot speak for other users, but I find the curve editor GUI in the Corona Color Correct Texmap difficult to use, i.e it takes much longer to arrive at the desired result. An alternative might be a levels adjustment editor instead, a la Photoshop.
If such a GUI element is already present in Max (or Corona), I would be happy to learn of it.
I would love to see a feature that automatically adjusts black level to the lowest pixel value, also white level to the highest pixel value. It would be very useful for remapping.
In the event that this feature is actually being evaluated internally, I wanted provide an alternate UI scheme for levels adjustment. The following comes from Substance Painter which enables levels adjustment:
Both the UI improvements for the Curves operator (numerical inputs, low/med/hi sliders, etc) and the Levels operator are acknowledged feature requests and we are aware that they are very much wanted.