I think its a fun and clever Idea, however I encountered a few problems with the syncing. On new keyframes, the previous set of eyes or lips would sit behind my new set and they would overlay each other (IE: Frame 1: Angry eyes added, frame 2: sad eyes added,...frame 30: unconcerned added, but overlays sad eyes). and I could't get it to go away. Other than that, I thought it was a nice feature to have.