Is there a way to block users from entering more quantity in item fulfillment than it is in VRA?

There is an accounting preference for allowing overages on Item Fulfillments. You would have to click it through, but I would think it works the same for SO's as it does for VRMAs

You could put a nag on a workflow that runs when saved. This would at least keep the user from over fulfilling a VRA if over fulfillment is allowed other places.

Okay, so I looked at that accounting preference. The box is unchecked, which means it shouldn't allow an overage. But it still did