Resolved an issue where custom mob spawners weren't applying your configuration settings correctly after updating to the 1.21.4 API. They will now function as intended instead of using the hardcoded defaults.
Further enhanced both the chest and spawner systems. You can now increase chest counts without issues; I tested it with 100% chest density, and it didn't crash (though I don't recommend this). For example, use 5% instead of 0.05% if you want more chests in the Overworld. The same applies to spawners.