RE: How to add multiple address in one Purchase order
                     
                    
                      
                        1. Various Drop Ship Address
    *** what is this purchase order for (Customer or other warehouse) 
         a. If Customer > that looks like Direct delivery scenario
         b. if warehouse > split the purchase order lines to multiple warehouse 
2. Reporting/Identification of PO Version Modifications 
   *** This is taken care with PO Confirmation Version e.g. PO No = USMF-000101, Order Confirmation would be USMF-000101-1, USMF-000101-2 and so on as per number of times you edit and confirm the PO.