Make Multi-Box Shipment Information Visible in API

As I understand it the information available in the ShipStation API does not distinguish between single-box and multi-box shipments. We need visibility in the API as to (1) how many boxes are in a shipment, (2) what products are in what box, and (3) the tracking number of each box. This information is essential for generating an EDI 856 (advance ship notice) document.