Allow purchasing to sent PO back for re-approval when increasing $ amount

A purchasing manager or buyer may increase a PO dollar amount exceeding the original approved amount. But the system does not have a way to get the PO approved again. Therefore, per our policy and for auditors, we have a separate change request form that must be signed and attached to the PO notes for any $ increase of 10% of more. An internal mechanism to return the PO for re-approval would very helpful.