I have the same questions. From what I gathered from this reply I made a ModFeatures class, where I register the ConfiguredFeatures, however how do I attach it to the BiomeLoadingEvent? I tried using the deferred registries the same way I did for blocks and items but it errors out because the block to generate isn't registered yet, even tho I am calling the register method in the Features Deferred Register after the Blocks Deferred Register