Can we change a GL Account# on a PO after an AP invoice created/matched fir the same PO line

Dear Oracle Procurement Guru:

The current state of Oracle will not allow Sourcing Department to modify a GL account#  on a PO when an invoice has already been applied by AP.

Is there a way to enable the GL account# field so that Sourcing Department  can modify the GL account# regardless if an invoice has been applied against the PO? 

We're running into this scenario more and more often and need to determine a feasible solution.

Allowing Sourcing Department to adjust the GL Account# on a PO at any point in time would solve our problem.

Thanks in advance for your feedbacks and support.