If an output is created for a changes to a PO that is not specified in 'fields relevant for printout of changes' configuration, that output will not be processed by ME9F.
In other words if a field is not marked as relevant for printout of changes, it will not be transmitted by ME9F in standard SAP.
That said, I don't believe its possible to prevent SAP from proposing a change output for specific changes and not propose a change for others. If you delete the entry as suggested above by another member, you will stop printout of valid changes also.