How to avoid flexible workflow restarting when purchase order is modified with a lower net value?

Hi,

we are looking for a solution to avoid flexible workflow restart when liberated purchase order is modified with a lower net value.

We have checked note 2800331-Fields which trigger a re-start of Flexible Workflow for PO but we would need only avoid restart of flexible workflow when lower net value is set on purchase order, and restart when a higher net value is set.

Is there any BADI which permits validate workflow restart with different conditions from customizing?

We found BADI MM_PUR_S4_PR_WFL_RESTART for purchase requisitions, maybe is there anything similar for purchase orders?

Thank you