That's a pretty nice plugin. I don't know if you're using it with the latest version of beets, but I'll give it a go, and hopefully it'll work. If not I'll try to get it working and send a patch if I do.

At the moment I use smart playlists and generate an "added today" playlist with all the songs imported to beets today, and add that playlist to my queue, appending it to the end of the queue.