Purchase Order - Approval Framework - Approving at a higher level

We are currently using Purchase Order approval using the WF Virtual Approval.  Users would like to use Approval Framework to get more transparency in the approval process and be able to use Ad Hoc approver assignment during the approval process. 

I have had some issues with setting this up in our development environment to work the way our business process operates.

Current state: Most of the time, Purchase Orders will go through the process of hitting each level of the approval rule set until it reaches the approval role with the appropriate amount authorized.  Other times, due to deadlines with vendors or customers, a higher level user will open the PO in the Approve Amounts page and bypass the process and approve it, skipping all lower levels who may or may not have final amount authority to approve.