The thing is, I'll bet the newly-regenerated stuff will be IDENTICAL to what's there, except with any new features. You may all have noticed that there's no "tearing" and weird joins like in original ragnar? I'll bet that's because of the map seed, which is now stored. If you make a new single-player map, you'll notice you can enter a randomizer seed. Enter the same twice, you'll get the same map twice. Same deal here. So you can trim something out, and it'll come right back EXACTLY the same. That's also why no tearing. It used to be a per-session random seed. Now it's one seed everything's based on, so no tearing.