On my PPre timeline is a video with no cuts/clips i.e. one clip with a time length of 13min. I want to edit a section (15sec) in AE so I cut the timeline where required, right click and select "Replace with AE comp". The AE effect I want to apply is Warp Stabilise to start with, followed by other editing/compositing. As you cannot apply Warp Stabilise to a comp I open the comp to reveal the movie. While the comp length is the same as the PPre cut, the movie is not. The movie duration is the full length i.e. 13min.
As I only want to apply the W S effect to the 15 sec section, is there a step in the workflow I am doing incorrectly or have overlooked?