Bukkit

So if I'm not mistaken, when trimming a map up to the border all exterior chunks get COMPLETELY DELETED right? Does this mean they also dissapear from the chunk data files inside the world file?

If this is so, Including an option on the command that respects protections such as: WorldGuard, Factions, GriefPrevention... (Most common) would effectively make this plugin a valid resource for chunk purging, by simply trimming up to a very tiny world border, and letting the plugin respect the claimed lands so that they don't get erased.

Chunk purging would have positive effects on reducing server disk memory usage, cleaning up unused (unclaimed) map chunks, which would consequently give a nicer enviroment look the next time someone comes near. (Imagine Factions servers clearing up all the mess players make regularly. How nicer the map would look for players)

There currently is no plugin capable of doing this efficiently. (Closest thing I've found for this purpose is WorldBeautifier, but being a paid resource whith a very inactive dev, the plugin does not function correctly and crashes the server.)

Of course I understand this suggestion may be a bit far fetched for your plugin, but I can assure you many people are looking for just the same thing for chunk purging.