Hi Christopher,
Thanks for raising this in the community! Currently, the answer is no. A purchase order is never uploaded to any integrated accountancy platform; only the inventory receipt is uploaded, and these go through a flow of draft > added to stock > Invoiced by supplier, which means you can’t reach the trigger to upload the bill (invoiced by supplier) without adding it to stock first. I do, however, think it would be worth voting for and adding your comments to the feature request for Proforma purchase orders, as this seems to cover the same situation.