Originally posted by M'Hael:

I think the upgrade world mod on nexus mod can regenerate your world while leaving your bases. I haven't personally used it yet, but I am planning to once some new content gets released. Definitely make backups before trying it.

Good point. It should also let you pull the new content into your existing world, that's kind of its primary purpose. But yeah, re-rolling the swamps for more iron should be viable too.

Originally posted by MistrBill:

It's a real PITA to mine the whole scrap pile without creating a Pond of Death

Mine them in reverse, bury them almost completely except for one tiny corner, and if the hitboxes line up right mining that corner can pop the whole node from above. It happens accidentally with silver sometimes.