Feature to Block Scanning the Same Serial Number Again Packed in SSCC but not Delivered

I am requesting a new Feature to the Packing workflow of Produmex based on the current design that the system does not have this functionality as a Standard Process.

Scenario & Feature Request: 

Scenario:
Item Code = ITM1000
3 X Serial Number Exist in the System = FR1000 , FR2000 , FR3000

1. Sales Order Created for the Quantity of 3 examples Item Code - ITM1000
2. The item code (ITM1000) on the sales order is managed by Serial Numbers
3. Picklist Proposal Created as Standard
4. Picklist Created created as standard
5. The picker picks the quantity of 3 from the pick locations - The serial Numbers Picked do not matter at this stage of the picking process as picking is performed to a moveable location to be scanned while Packing.

6. The Packing Emulator is executed.
7. The Packing line is selected
8. The moveable location is selected
9. The stock on the moveable location is displayed as standard
10. The Packing user on the packing screen selects the ITM1000 and selects the quantity 1 rather than 3 as a standard process
11. Add Item Clicked
12. The current system design of WMS prompts the user to scan the serial number.
13. As the required quantity is 1 so the first serial number is scanned (FR1000) and press enter.
14. Use the Forward Arrow to confirm the line is packed
15 Enter the cart manually again (movable location selected) -
16. Select the Item - ITM1000
17. Change the Quantity to Pack as 1.
18. Add Items Clicked
19. As the required quantity is 1 for the second time so the previously scanned serial number (FR1000) can be scanned again and unfortunately the WMS current design does not stop and let the user scan the same serial number (FR1000) and press enter which then result that the delivery note is not created. 

Proposed Solution Suggestion for this Feature:

Based on the scenario described above, The proposed solution or feature to the Produmex WMS packing workflow would be if the serial number is already scanned as part of the Packing process onto an SSCC and moved to the shipping Dock but not yet delivered as (SAP Delivery Note or PMX Shipping Note) then Produmex workflow should need to stop the operator from scanning the same serial number again onto another SSCC.

User Message for this Feature:

Error Prompt and message that can help the user is that the Serial Number (XXXXXXXX) has already been scanned on SSCC (XXXXXXXX) and Dock (XXXXXXXX). Cannot scan the same serial number again. This feature will block the operator from scanning the same serial number multiple times in a Packing process.