Did you know that when creating territory proposals, you can restore the past state of your territory structures? Of any moment back in time?
All you need to do is create a new territory proposal, and use the restore option
Pick a date of any moment in time in the past, and restore the territory structures inside your proposal as it used to be at that moment in time!
Not only is this useful to restore parts of previous territory structures, but also to run a comparison/analysis between the current territory plans, and the temporary restored ones in your proposal.