Warehouse Management - Shipment Pick

The default for Navision is to only allow pick creation for shipment lines with Qty per UM = 1. We have a product that is sold in UM = CTN which is 4 items on a pallet. This detail helps with the BOL, but Navision won’t create a pick for it. Has anyone else run it this before and has anyone made a mod to allow other UM’s to be picked? Thanks in advance for your help.