Hello Aternos Team,
Can you please add the mod "ProtoSky Mod".
Link to the mod : https://www.curseforge.com/minecraft/mc-mods/protosky-mod
ProtoSky Mod is a very simple generation mod that just create a default world but without blocks (it keeps biome and structures bounding box).
It is the best mod to make a 100% vanilla skyblock (even if this is a mod lol).