Stopping SL, found on the left side of the main window with the render settings, makes Chaotica stop rendering at the desired sampling level when checked (instead of the normal rendering mode which never ends).
When combined with batch mode, this is useful for rendering large numbers of paramsets at once, such as when making an animation. Once stopping SL and batch mode are both checked, use the "..." button to select the directory in which to save completed renders. Chaotica will then render every paramset currently listed in the world editor.