Sorry if this request pops up twice: I had issues filing.
I use UniWB, see: http://www.guillermoluijk.com/tutorial/uniwb/index_en.htm
This allows me to get a better representation of a RAW histogram in the camera.
The trouble is the custom file gets erased when I erase the images on the card.
I wonder if ML could be made to read a custom WB file and keep this file on the ML side; that is it doesn't get erased.