KeyTweak is a powerful After Effects script to modify many keyframes of a property at once. It can be used, for example, to refine a rotoscoping mask without the need to touch every single keyframe separately: Just correcet a few keyframes by hand and KeyTweak adjusts the remaining keyframes accordingly. KeyTweak is not limited to masks, but also works with other keyframed properties. You can also use it to correct drifting tracks.
KeyTweak […] achieves the seemingly impossible: Edit a keyframed mask globally simply by points on one or two mask keyframes, and the rest are automagically changed 'accordingly'.
Wow this maybe the most productive After Effects script I've come across!! Adobe should pay you for it, and integrate it as a stand feature!