Minecraft wiki entry for Configured_feature, associated text: pointed_dripstone
 chance_of_taller_dripstone: (optional) Value between 0 and 1. Defaults to 0.2.
 chance_of_directional_spread: (optional) Value between 0 and 1. Defaults to 0.7.
 chance_of_spread_radius2: (optional) Value between 0 and 1. Defaults to 0.5.
 chance_of_spread_radius3: (optional) Value between 0 and 1. Defaults to 0.5.