An easy-to-use plugin to regenerate chunks in your Overworld, Nether, or End!

Installation:

Put ChunkRegenerator.jar in your "plugins" folder, and start the server.

Commands:

/chunkregenerate here ("fill" or "nofill") ("frames" or "noframes")
Regenerates the chunk you are standing in, from bedrock to the sky (Refills chests, brewing stands, minecarts with chests etc... if "fill" is used, regenerates the item frame in the End Ship along with the Elytra if "frames" is used);

/chunkregenerate chunkx1 chunkz1 chunkx2 chunkz2 ("fill" or "nofill") ("frames" or "noframes")
Regenerates all the chunks in the area between the (chunkx1, chunkz1) chunk and the (chunkx2, chunkz2) chunk, extremities included, from bedrock to the sky (Refills chests, brewing stands, minecarts with chests, etc... if "fill" is used, regenerates the item frame in the End Ship along with the Elytra if "frames" is used);

/chunkregenerate undo
Undoes your most recent operation, even if nobody is present in the World the regeneration was done
(The default number of max operations saved is 64, you can edit this number in ChunkRegeneratorConfig.txt, that will appear in your plugins folder after the plug-in has been activated once).

You can find chunk coordinates with F3, Under your normal coordinates, ignore the "y" as the plug-in regenerates everything from bedrock to the sky!

Examples:

/chunkregenerate 0 0 1 1 fill noframes
Regenerate chunk (0, 0), (1, 0), (0, 1), (1, 1), equivalently the area between (0, y, 0) and (32, y, 32), along with chests contents, brewing stands contents, minecarts with chests, etc..., but without regenerating the item frame in the End Ship along with the Elytra.

/chunkregenerate here nofill noframes
Regenerates the chunk you are standing in, without resetting chests contents, brewing stands contents, minecarts with chests, etc..., and without regenerating the item frame in the End Ship along with the Elytra.

Hard-disk space:

For every World in which you want to regenerate a chunk, a maximum of ~5MB of memory is required, no matter how many chunks you want to reset, or wherever they are in the world (For a maximum of ~15MB of memory for a complete set Overworld / Nether / End).

The World "ChunkRegenerator_Undo" will contain your previous operations done with this plug-in, and will slowly grow in size in accord with how many operations you decided to save and are currently saved, these operations will be lost when the server restarts to free Hard-Disk memory.

Server load :

When regenerating a chunk for the first time in a World, the command will take some time. After that, the load will depend on how many chunks you are trying to reset at once.

Known issues:

1) The behaviour of the plug-in is undefined when trying to use the command in a FLAT, LARGE_BIOMES, or AMPLIFIED World;

If you find an issue not already listed in "Known issues", let me know!