We don't need the -z option in the rsync for sync_offline, the -z compresses the data as it is moved, which is unneeded when copying from local directory to local directory
Why does the biome) section copy the EXTRACTEDBIOMES from the world-offline into the world folder? it doubles the size of my backups and is almost completely unnecessary, considering how quickly the biome extractor runs, even from scratch, so keeping a backup copy of it is a huge waste of space.