Manual Tax Code change warning

It would be good if a warning message showed when a manual tax code was applied to confirm if this will change current month, or the next payroll run depending on the status of the payroll so we are aware when the change will be in effect from. For example, if a manual change is applied when the payroll is closed, it would be good to flag this wont change until next open run (even if you re-open last payroll)