one example can be shown here http://puu.sh/sHPYc/b5276869b3.png overwriting garden of glass

also the json that overwrited this preset void overworld template"=skyblock_2-1_overworld.json

this also overwrites a backed up world also making a another skyblock within the backed up world

the json used from config is: void overworld template"=skyblock_2-1_overworld.json

Sorry for not responding sooner. You could replace "skyblock_2-1_overworld.json" with "none" so the line looks like
S:"void overworld template"=none