Question - Can Approver Who Has Proper Authority Approve a PO that they Modify?

PO Document Types are set to:

Purchasing Setup > Purchasing > Document Types > Award Standard

Owner Can Approve = NO

Approver Can Modify = YES

Workflow Approval = PO Approval

Forward Method = Hierarchy

PO Owner is X

PO Approver is Y

PO Approver is Z

If X submits a PO for Approval and Y Modify's it (and Y also has the Authority to Approve the PO) will the system allow Y Approve the PO even though Y Modified?

Or because Y Modified, then system would require Z to Modify it?

Real Situation: X submitted a PO for Approval. Y Modified it (and Y also has the Authority to Approve the PO). Y also Approved the PO.