Mhm... makes sense. But: If I do it your way, then the database quota is independant from web quota, isn't it? That alone doesn't hurt, but will I this way have the possibility to limit the total database space my resellers can give to their customers? Or would I have to make bigger changes?
Btw, if you're planning to integrate the script into ISPConfig, then I'd love to use its databases. Otherwise I'd prefer to use a seperate db, because I don't want to fall into trouble when I'm upgrading