Minecraft wiki entry for Configured_feature, associated text: delta_feature
 contents: The block to use on the inside of the delta.
Block state[show]
 rim: The block to use for the rim of the delta.
Block state[show]
 size: Int provider between 0 and 16.
Int provider[show]
 rim_size: Int provider between 0 and 16.
Int provider[show]