It's an interesting question, but would require quite a fair amount of development to make it work. You could add new columns to qa_userpoints, and keep those columns updated whenever a question or answer was created, edited, hidden or deleted. All the relevant functions are in qa-app-post-create.php and qa-app-post-update.php. You would then need to make the appropriate modifications to the query in qa_db_points_update_ifuser(...) in qa-db-points.php.