Tested as documented here: http://www.phreekz.de/wordpress/2013/06/magiclantern-raw2cdng-cinema-dng/
11.08.2013 – v1.3.0 – whitebalance from cr2
Doesn't seem to work, unless I'm doing something wrong.
As a feature request, it would be good if the UI could note that it found the .cr2 file and will be referencing it.
If I get time, I'll look into it myself.