About STEAMPUNK HEAP biome:

This is a ‘mask biome’ that will turn "Visceral Heap" from "Biomes O' Plenty" mod into something far less ‘fleshy’.

Those who don’t want to play with this ‘mask biome’ can delete the "biomesoplenty" folder inside the "assets" directory of the current texture pack "FeelTrue_x32_Unlocked+.zip."

If instead you want the freedom to choose when to use it, then in addition to removing the "biomesoplenty" folder, you have to download the "MostlyTrue_Worlds_Unlocked+" texture pack and place it above the current "FeelTrue_x32_Unlocked+.zip" texture pack.