We made this change to our production server and thought the community might find it useful.
Islandora uses a fairly small number of XSL transforms for converting DC to MODS and vice versa, in addition to other transforms. Unfortunately, the small number of transforms tend to get duplicated across modules.
Example problems include
empty dc:subject elements in the OAI DC
empty dc:subject elements in the DC datastream
duplicated dc:date elements
May need to add this file to the following modules as well to operate without errors:
Pull Request: https://github.com/Islandora/islandora_batch/pull/83