Okay, that seems to do the undesired thing of killing all file indexing on the system. I removed one file and added a different file, and those changes were not reflected in the database of movies on the NAS, even after telling it to do a full re-index. Additionally, the re-index processes never finished, making me think that perhaps they locked up.

So from the looks of it, that file controls all file indexing, not just the metadata lookups. But we're on the right track.