No, I think the UI uses building blocks. There doesn't seem to be a whole lot that's different about Rastar that wasn't already covered 2 years ago at citizencon: https://youtu.be/fQkN1YdT6SI?t=491
I think maybe the original outposts were built without using this tool? It's more feature complete now and so they're using it to revamp all the existing bunkers. At the end of the day, nothing changes for the players besides the exterior layout of the area around the bunkers.