Dual UoM: Fractional Secondary Quantities

Client is a food manufacturer that manufactures full containers of foodstuffs.  These items have an Item UOM Conversion (1 EA = 500 LB), but each container is individually weighed and serial numbered.  (FIFO processing is important, this is why the serial numbers are needed.)  They enter a SO for 10 units, so they enter 5,000 LB (Primary) and 10 EA (Secondary) on the SO line. 

They do not run Pick Slips, they pick the items first, then they use the P4205 for Pick Confirm.  After pick confirm, they have 10 SO lines, because the system commits the serially-numbered items from the F41021 records to the SO.  The first line will be status 540/560, and the other lines will be at status 914/560 (914 is 'Added in Ship Confirm').  At this point, each line will have a quantity of between 475 and 525 LB, and the Secondary Qty / UOM will be 1 EA for all lines.