When “ship to customer” is chosen in the POS, the CarrierService apps callback_url is called to obtain shipping costs for items in the cart.
In some circumstances, a single call is made to the callback_url that contains all items in the cart. In other circumstances the items in the cart are dived and multiple calls are made.
What causes multiple calls to be made vs. all of the items being contained in a single call. Is this documented anywhere? Is there any way to ensure that only a single call is made.
The POS app “select shipping rate” page displays results only from a single call. Is there any way for the POS app to gracefully handle multiple results for a single cart?
