Fulfillment set for two different orders possible?

Hi

I have a requirement as below.

The flow generates from Oracle Depot Repair.

I am receiving an item for repair through RMA (ex:5670). Line 1

On the same order I ship the item after repair Line 2.

The repair charges for spares used and Labor as well billed in the same Order (5670) line 3 Line 4 as Bill-Only Lines.

as in any case, without shipping the item we will not invoice the customer so I am adding my ship line + all Bill only line to a fulfillment set. This is fine.

But if the customer gives two different PO seprately for Material and another PO for labor then we need to send two different invoices.