These can all be cloned or made in the editor in generated maps, but you cant even use them. They would add a lot of extra new content to the game.
You could have biomes added to the mods download section for custom games.
You can make them but cant use them in your maps
You can clone some of the individual data, but the part where it (seemingly) gets hooked up to the UI, you can’t:
Without creating a game mode (or a map), anyway. This is just with the tuning data.
There’s a fair bit modders are restricted by - it’d be nice if parts of it could be opened up more 
