Voicey99, Thanks for the detailed reply and info!
If the auto-shipping of resources uses a Hohmann transfer, it will probably be too slow to be practical. For me, with all these colonies, money is not an issue. It's possible to build a big expensive 3-stage nuclear rocket and get stuff to Leto in around 9 years or so. So it would be nice if the auto-shipping feature allowed a tradeoff between cost and travel time. But I expect that would be difficult to implement.