I would like to load, in the undo graph, the history of "personal best" positions - ie a record of each time my score moved forward. Playing this would look like the videos of best puzzle solutions that were posted some time ago.

Why it would be useful:

From time to time, it is worthwhile to compare the current status with previous positions. Maybe an effective redesign in an area was accompanied by a change in another area (e.g. sidechain position) that drags the score down. Comparing with previous best positions would help identify those potential problem areas and fix them. Also, this may give a sense of where the puzzle solution is going...

GUI implementation suggestions:

(1) Add a button to the undo panel that would replace the content of the undo graph load by this "best-to-best" undo graph.

or

(2) Make it appear "before" the current undo history. If the cursor is at the beginning of the undo graph, pressing "Undo" again would display the best previous position, then the previous best one etc. Although there may be a scale issue to solve.

I hope this is clear.