First of all, thanks for the plugin, it's awesome.
I read some of the info you have for adding a site, but frankly python is way over my head. I was going to ask for Adultfanfiction.net, but saw you won't add it sadly. It is completely adult oriented, hence the over abundance of warnings.
Anyway, could you maybe add
HP Fandom.net?
It's an old eFiction based site (1.1 I think) and it's a large archive, actually one of the largest all Harry Potter out there.
Then there is
Walking the Plank.
Hopefully you'd be able to add them.