Add a new clip without rebuilding the composition

[wimansha]

I am playing a few video clips together by using this marvelous library. Also, from time to time I need to append a new video clip and play the whole video just after adding it. When the videos amount increases it takes more time to regenerate the play item.

Is there any way to remove this delay?
Can we do changes to the timeline dynamically and see them on preview(player item) without rebuilding the composition?