How can the Mixed Order (Sales Order Type of MO) process a shipment for the item being issued?

The customer walks in to the counter to return and replace an item.  The replacement item must be picked and processed in the warehouse but the mixed order type cannot do a shipment  Using the RMA order type requires a Receipt to be processed.  There is not a desire to go thru the entire shipping process for the receipt, just return it to the default RMA bin (MO orders DO NOT default the location to the RMA location which is a bug).