This update introduces an efficient method of biome setting for the whole world. This is only viewable on the Minestom server when you load the polar world.
To set the world's biome, do /data add Biome {Name:"name:space"}. name:space is the namespace of your biome defined in your Minestom server.
To use the setup, go to the initial release and replace the plugin inside of that release with this one.