The only way to allow Smoothcam Filter to analyze just the clips that you need is to make reference or self-contained movies for the clips that need it.
As both a shooter and editor, I would recomend shooting steadier footage and you won’t need to use Smoothcam on a lot of your clips.
As an editor, if someone handed me a tape with lots of shaky footage, I would charge A LOT OF MONEY if I had to fix it.
Steve Eisen
Eisen Video Productions
Director-At-Large
Chicago Final Cut Pro Users Group