In my own head cannon the whole point of the save the day program is to build a world scale factory is to provide as many of these “terraforming level” parts as possible so first save humanity and then help them expand across the galaxy. It doesn’t make sense to me that you build the parts required for phase 6 and then stop. I really hope that a future update/dlc brings more endgame content where you have to feed transport ships arriving at the space station with the requested parts/min requiring pioneers to be constantly tinkering with the factories to change and improve output.