As multiple tax registration numbers feature is now supported in a single legal entity, it will have chance to have different warehouse/site at document line level from the header, which will lead to the List Code value is not correct at document header level.

A simple example as below:

A German legal entity has two warehouses in France and Germany. When creating sales order with a German customer, the default warehouse at header will be Germany and List Code value will be Not Included. However, if the warehouse at order line level is changed to France, then the correct List Code value for this transaction should be EU Trade. If user forgets to update the List Code on the header, then mistake happens.

So if List Code can be supported at line level, it can help validate if the value is the same between header and line to avoid manual mistake.