I expect a kind of leapfrogging. Scout ahead, build a gate and/or infrastructure/terraforming, then a small fraction will decide it's worth migrating. Repeat.

I expect a kind of leapfrogging. Scout ahead, build a gate and/or infrastructure/terraforming, then a small fraction will decide it's worth migrating. Repeat. Expansion will only go as quickly as travel time allows. Even the speed of light seems insufficient beyond a certain point. We will want to manipulate space.