[1.16] Overriden minecraft grass block is missing from world gen

[Sekai Red]

Hello, I was trying to override the vanilla grass block spread behavior by registering my own grass block and implementing it's own random tick function, it seemed to work in an all dirt superflat but the moment I created a regular world, all grass blocks are missing and patches of sand, gravel and pumpkins are floating up. (https://i.imgur.com/9fYC5YF.png)

I have to assume this field is the culprit because of it being static and DeferredRegister happening later. (along with some in other world gen classes that cache the old BlockState)

public abstract class SurfaceBuilder<C extends ISurfaceBuilderConfig> extends net.minecraftforge.registries.ForgeRegistryEntry<SurfaceBuilder<?>> {
   [...]
   private static final BlockState GRASS_BLOCK = Blocks.GRASS_BLOCK.defaultBlockState();
   [...]
}

I tried to use reflection to fix this but it doesn't seem to change things and is probably a bad idea, is there any way to fix this or is it better to avoid overriding any vanilla blocks and instead have my own replace them in generated chunks?

https://github.com/SekaiRed/GradualGrass