Oh, that's true, the Ekumen do get the long-term perspective another way. I remember a bit in LHoD about ideas and people being basically the only things practicable to send over such long distances, and trade in bulk goods, and war over resources, not being reasonable. But that's more about distance tempering human aggression, not time.

It sometimes feels kind of colonial, now I think of it, when there are less long-lived planets being managed in this way.

In what way? Aren't all the people basically the same species but with variations, and have equally long lives? Or do you mean how far/near they are to other planets, and the technology level they have?