Need Serialized part only for Shipping

Hello Team,

We would like to have part which can be backflush in WO as child part as well as it should be shippable to customer. We need this part as serialized ONLY while doing the shipment. We don't want this part serialized control when it get back flush in work order.

I tried to make the setup the item level attribute i.e. Serial generation as "Entry at Sales Order, Transfer Oracle or Work Order issue" but its not fulfilling the requirement.

Can any one help to know if we have any other setup to fulfill above requirement OR