Idea: introducing a snapshot function and a snapshot timeline into the soon to be overhauled ( ) planner? Something like this:
Example:
Sometimes you plan a route to a destination, but you are not sure whether to go over or under a certain in between city. This way you can plan until in the neighborhood of that city, create a snapshot there, plan northways, revert to the snapshot, plan southways, and consider the difference. You can consolidate the route by deleting the snapshots you don't want at the end.
EDIT:
that second number 3 should have been a 4 of course