when i first tried it, the plan which they had just scrapped was to have the biomes and general features be static but the details be procedural. so the skin of each part of the map was changeable. this was after the seamoth but long before the cyclops, when all the upgrade parts were untextured safes and all the biomes had not been added yet. there was one corner of the map that was just flat.

at that point they still had terraforming stuff. in fact that’s how i first explored the big hollow trunk in the plate coral forest biome: i blew the top off. i don’t remember if i went there right after the update that added the biome or had to wait for a month, because at some point in the development you couldn’t even look at that part of the map without fps dropping down to fractions. i think they forgot to use instancing so each model used its own drawcall, and there are thousands of them in that area.