Configuring Oil Sprouts
This feature is named raw_oil_sprout, not raw_oil_spout.
Oil Sprouts are generated via Minecraft's "Configured Feature" system, and can be customized via standard datapacks.
If you are using kubejs, placing files in the kubejs/data folder is equivalent to adding files to a datapack.
Removing Oil Sprouts
To disable oil sprouts entirely, place the following file in kubejs/data/gtceu/worldgen/configured_feature/raw_oil_sprout.json,
or create a datapack containing the equivalent. This will replace the sprouts with a no_op - i.e. a feature that does nothing.
{
"type": "minecraft:no_op",
"config": {}
}
Adjusting Oil Sprout Placement Conditions
If you just want to adjust the rarity of oil sprouts, that is configured via the "Placed Feature" system. Copy the
current version
of the placed feature file to kubejs/data/gtceu/worldgen/placed_feature/raw_oil_sprout.json, and modify the settings
as desired. (The default file uses a "minecraft:rarity_filter" to give a 1/64 chance of each chunk containing a sprout.)