The Control bar and the contextual task bar copied the first selected
object every frame (the task bar twice), which on a path of 200,000
anchors costs about 1.4 ms per copy. Both bars now borrow it; the task
bar copies it only when it is a basic shape, for Shape Properties.
With one selected open path of 200,000 anchors, an idle frame with both
bars shown takes 3.8 ms instead of 8.0 ms in a release build.