So I've gone to something straightforward this week. I think that POP batches, Receiving, Shipment Invoice and Invoice batches should have batch approval functionality similar to AP. In the case of Shipment Invoices and Invoices in particular, these actually create AP batches and sometimes AP wants/needs to control the posting.
I know, the approval should really be at the P.O. level but since you can over/under receive and change the cost (depending on settings) some companies want a double check before sending this to payroll. If you'd like to vote for this go to:
https://connect.microsoft.com/dynamicssuggestions/feedback/details/760005/pop-invoice-match-batch-approval