IIRC, EvilLyrics has no database, per se. It searches a bunch of well-known lyrics sites, and if it doesn't have any luck on those, I think it just Googles the title and artist and pulls up the first hit or something
Adding that kind of logic into this plugin would seem non-trivial, and be a duplication of what could already be done if lyric submitters use EvilLyrics, paste the lyrics into Patrick's plugin, and go from there. Having it in one nice package might be nice, but I'd rather see other stuff like lyric submission to our own database first.