Towny: Wilderness Regeneration

So I understand the wilderness regenerates from explosions gradually (if set), but I have some queries...

I want people to be able to build and destroy in the wilderness (to mine, craft, hunt etc), so to save the world from being destroyed beyond recognition eventually, I want the world to regenerate very slowly (e.g. per 60 seconds, so a minor doesn't become trapped and benefit from constantly regenerating ores). Is there a way or an extra plugin to do this? I feel that dedicated mining zones is a big deterrence.

How does the snapshotting work when the regeneration references the default state, is it literally as the world is first generated?