DFF Value Set

We have a context sensitive dff and value set on the miscellanous transactions form, making attribute1 required if a specific transaction type is selected.  The value set retrieves the list of active employees clock numbers.  This works great, the problem

I have encountered is that when users go into the Material Transactions form to view old transactions and they hit an old transaction where the user is no longer active, they receive an error that the value does not exist in the value set (which is true , it no longer goes because the employee is inactive)

Does anyone have any suggestion on how to still limit the value set to only show active employees when users are creating transactions in the miscellanous transactions form but also allow the Material Transactions form to show all values, active or not?