Individual Chunk Regeneration with different settings? (Using Cleanroom in combonation with DEFAULT)

I am not inexperienced using craftworlds, but am inexperienced with ChunkGenerators. I am making a plugin that will work with CleanroomGenerator to create a world that has the chunks in the center of the map being 20 blocks higher than the center of the map so there will be a huge square hole where people can build in, like a favela or gulag,
The primary problem is I wish to be able to use a tool to automatically regenerate the chunks in the center because I know I can use McEdit to create the depression in the map but I need to be able to regenerate that center area quickly if the chunk is owned by a griefer.
It will look something like this:

the center of the crater being about 8 by 8 chunks. Any help would be appreciated.

 

you can use your own made world generator