Simply removes the planet-based build restrictions on everything (gravity/pressure/magnetic field). In future hopefully I'll paywall it behind research options. For now I'd recommend not installing until you are on your way to the Edge, so you get to experience the frustrating progression of Gleba like the rest of us. Then you can relocate and consolidate to any planet you like.
Snippet of code was lifted from Spaghetti2364's "Everything on Nauvis" mod so all credit goes to them.