@Tanjamuse
Yes, I'm doing that currently anyways. The "Buffy the Vampire Slayer" category should be added automatically, which you could replace to what you want with replace_metadata.
You can also use any of these. If you decide to use "extracategories" though, the default I specified will be overwritten.
Code:
## extra categories, genres, characters, ships and warnings can be
## configured. Used primarily for sites that are dedicated to a genre
## or 'ship and so don't included it for every story.
#extracategories:
#extragenres:
#extracharacters:
#extraships:
#extrawarnings:
@Bobthebilder
I'll see what I can do when I find time.