
limiting the chest-amount to desired volume, so that if low volume the oncoming cart will fill it up and then to the next station.
I don't see a real need for such a complicated steering, especially with so low a volume that a belt is not an option.
you can limit the chest easily to connect the inserter to the chest and set up a threshold when the insert is working.
beside with a ever circling cart there is a given chance to have a shorter response time because eventually a cart is already on the way.