Purchase Orders not showing as Complete when Over Invoiced

In Sage currently, it is possible to over-invoice on a Purchase Order. So in POP, a Purchase Order could have a line with quantity of 100,100 are then receivedand then a Purchase Invoice is recorded with a quantity of 150. When amending the Quantity to Invoice, there is a warning shown but it allows you to continue recording the Invoice. Once the Invoice is recorded against the Order, the Purchase Order still shows as Live and the only way that it can be completed is to use the Write Off Incomplete Orders Function and then the User also needs to add in the extra Stock if required. It would be beneficial if the User was made to amend the Order and Received quantity if the quantity on the Invoice is greater than the Order Quantity as it seems unlikely that the Customer would be Invoiced for a higher quantity than what is on their Purchase Order.