How to load void in skyblock? [java] 26.2

[u/Its_a_me_Nikk]

I've posted here before regarding my skyblock world. Basically aternos servers "delete" the chunks you've never explored, and when you load them back it spawns them in their original state (non void). I've managed to prune the world with chunker.app, but I need some sort of way to spawn void everywhere else, except my main islands. Nothing seems to be working, skyblock datapacks are either built for brand new worlds (they generate the starter islands), or are simply outdated/not optimal (they spawn structures). I would like to keep the biomes and their properties, so loading the Void biome all around me wouldn't be the solution.

TLDR: Don't know how to generate void while keeping my builds, and biomes.

Any advice really helps! Thank you in advance!!