If it works anything like the conduits it could work on a point-to-point basis. Inventory B has space for an item, so inventory A send out items until inventory B is full. Of course, travel time could cause more than needed to be sent unless it counts the objects still in the item ducts as already being inside their target inventories. hopefully though it's something where overflow isn't an issue and it doesn't add much or any lag.



Edit: Another possible way this could work is if inventory B tells A "hey, I have space for X items right now, send them to me" and then A sends out only that amount of items and B doesn't make a request for more until its initial order was fulfilled. This would have the effect of there being some time gaps on when he items are sent though, and I'm not sure how it would work with the round-robin pipes unless that setting acts like an interim inventory A for target inventories, say, B and C. Basically, B and C would see A has items and both request the same amount. The round-robin pipe will then say "shut up, I'm only giving each of you this amount." Of course, this is all conjecture at this point.