Mmm Not really. Dev's could supply two verisons for example (one for each route).
If it was me and I had chosen route A then id be satisfied with a suitable save to that point for that particular route or mc, and be happy to start over from a sensible point to Select Route B....
Dev's HAVE to think ahead for this sort of thing, otherwise your going to get nowhere writing sensible updates and development if this isnt catered for, no matter which field your writing for...
Anyway, this isnt about saves really, its just that there are not suitable catches in various points to cater for areas perhaps that have not triggered when they should.
Im sure a solution will come up