Chests have been fixed, and the plugin has been polished up and finalized

Added:

Chunks will now be inversed in the Nether as well as the Overworld.

Spawners previously reset back to a default pig spawner, which has been fixed.

Updated API to 1.16.

To do:

Chests sometimes drop their items near them instead of switching the contents correctly. I am working on a solution to this issue.