If they return it back, don't you just need to create a PO, bill it and apply that credit from VRA?
The item fulfillment from VRA and the item receipt from the second PO keeps track of the movement of the inventory in the real world. If you won't do this, how will you track the movement? Inventory adjustments? Transfer Orders/Inventory Transfers to dummy locations? That does not seem nice as well tbh.
Maybe custom record or fields for the ones you want to accept but still record the quality issues?
Have you explored the Quality Management module of NS?
I'm curious what other people's thoughts are on this.