Brian, are you sure that both are LIBRARIES? I just looked at one of my sites, where I am using v4.4.5.14 of DFFS, and when I apply DFFS to a LIBRARY and look at the Hidden Fields section in the MISC tab in the DFFS configuration, no columns are showing.
When I apply DFFS to a CUSTOM LIST and look at the Hidden Fields section in the MISC tab in the DFFS configuration, all the list columns are showing.