It removes all bedrock in the bottom layers.
It then puts in a flat layer.
No holes and no random blocks.
This searches the bottom 10 layers for any bedrock, replaces it with stone, then puts a flat layer back at level 0.
It won’t do chunks already created, but every newly generated chunk will have flat bedrock.
It takes this:
and makes it this:
Yes, it does preserve what is already there.
Video By: Me
Video By: SCMowns2