I think this tool should be able to work on any point along the figure and become Figure Adjust Point. I think that it might require the picking of a reference point since the adjustment might be forward on the path or it could be backward.
This tool has been revised to work on any segment along the figure. Pick the segment near the end you want to move, the other will be held fixed. The base and pointer graphics (immediately after pick) make it obvious what's going to happen.