Sounds like a nice thing. Although I think I'll continue doing that manually. I have a habit of evaluating the content that I've got from torrents. I do it in my mind explicitly. And then I share longer proportionally to how good the thing was, and how rare I estimate it is. This is decided once and doesn't change after, with a built-in "share ratio" limit. Once a torrent reaches its ratio and becomes Paused, I know that it's done and can be removed.
In the beginning, all torrents stop as soon as they finished downloading, to let me evaluate the content. (Uninteresting stuff I intentionally don't share back at all.)