It would be nice to be able to specify a "direction" for depots. For example, when the rare metals are extracted, I'd like to be able to set up the depots so that the shuttles will only pick them up from the source depot and drop them off at the depot next to where my rockets land. (It does this for the space elevator, but only because that depot is right next to the elevator which always wants to "consume" the rare metals.) The same goes for food. I'd like to be able to designate that certain food depots are "sources" and the outer domes' food depots are "destination". It currently kinda works like that now, but I've still had shuttles re-grab food that I've manually transported to the outer domes and bring them back to nearly empty food depots where the farms are. Very frustrating.