1.21 Update:

Added chest items for Overworld:

• MACE
• OMINOUS_BOTTLE
• OMINOUS_TRIAL_KEY
• TRIAL_KEY
• BREEZE_ROD

Added spawner entities for Overworld:

• BREEZE
• BOGGED

Added blocks for Overworld:

• CHISELED_COPPER
• COPPER_BULB
• COPPER_GRATE
• VAULT
• TRIAL_SPAWNER
• HEAVY_CORE

For VAULT and TRIAL_SPAWNER there is a 50% chance applied to determine if it will be set Ominous.

Note: These blocks where added to the default files, you can still add any other blocks from the available in the materials page.
https://hub.spigotmc.org/javadocs/bukkit/org/bukkit/Material.html

Pre-generator Rework:

- Usage: /pregen <ParallelTasksMultiplier> <PrintUpdateDelayin(Seconds/Minutes/Hours)> <world> <Radiusin(Blocks/Chunks/Regions)>

For more information you can check out the page here.

Bug Fixed
- Fixed some issues with pregenerator unloading chunks to soon,
- Extend unloading until chunk is entity ticking to ensure chunks are fully generated


Made my own simple data pack Void-Biomes-1.21, currently Void Worldgen has not been updated to 1.21 yet, so in the future if you want you can use that instead.
- The data pack only generate the biome data for the Minecraft worlds, the only structure is the end portal and pillars
- The Void-Biomes-1.21 data pack should improve performance (~20%) if used in place of the old Void Worldgen data pack since it is not generating structure boundary boxes for any structures.
- You can get the simple data pack here, Void-Biomes-1.21