Let's say you're in an isolated start. There's a clump of planets near you, but you're on the corner of the map and there's a big empty gap between you and the rest of the galaxy.
Can you build a constructor and make a starbase in the middle of the gap to bridge your units across to the other side? That way you don't have to waste valuable early research points on an otherwise useless tech of life support. Furthermore, you can ditch the life support modules on your colony ships and instead outfit them with more ion drives.
