Easy mode: Delete only what does not fall within the radius of the radar.

Options:
Remove chunks before saving
Delete chunks as the game progresses gradually, but not all at once (for example, a chunk visiting timeout of 30 minutes)

"*" - in order to remove from all found worlds.
(I play with the Space Exploration mod and it creates a lot of surfaces, I would not want to set all their names manually)
Or add the ability to specify a mod that adds new surfaces to remove only surfaces related to this mod

sorry for english i use google translate