The primary benefit whether connected in a Supply Chain or not is the availability of information on the cost of importing products. In a Supply Chain you benefit most by seeing the status of incoming PoGs at both the Supplier level and at Agents handling the goods.
When connected in a Supply Chain you can create purchase orders and make them available to connected Suppliers.
When connected in a Supply Chain you can reconcile purchase orders when invoiced and shipped by connected Suppliers.
If not connected in a Supply Chain, you can inform your connected Broker about PoG's you are purchasing.