This feature is available only in kJams 2.0!
You can turn ShowScreens into "song" entries in your Library (or put them in a playlist). This way you can just "play" them as if they were a song.
This feature is not quite ready yet. If you hold down the "option / alt" key while picking a ShowScreen, kJams will create a new "song" by the name of that ShowScreen. I do not think "Rotation" works quite yet, but it WILL soon.