Just as the timeline for overall modeling is incredibly useful (I could hardly do without it) there are many times when I'm creating/editing a SKETCH where it would be very helpful to have a timeline of all the sketching operations I've done on the sketch. It's pretty obvious that there IS such a timeline internally, since it is possible to use the UNDO button to back up, so it ought to be possible to make that timeline visible, perhaps as a temporary Sketch timeline that pops up above the modelling timeline and disappears once the sketching is done.
At the very least such a timeline would be useful when UN-DOING some recent operations, so that you could see, visually (via sketch operation icons), what operations you're deleting. But I've also encountered situations where I want to delete or edit other sketch objects and it would be helpful to be able to view and locate them in the sketch's timeline. In addition, there are times when the deleting of something in a sketch causes problems "down-stream" with other objects relying on prior objects, just like in the normal model timeline. It would be nice if, as in the normal timeline, we could see such impacts (e.g. yellow highlights) in a sketch timeline.
