Is it possible to use Punchout with Oracle system items for your stockable items?

I realize catalog content for inventory items is best handled with internal catalogs, but am wondering if it is possible and not difficult (meaning mostly configurable) to use punchout with Oracle system items.

Can a supplier cross-reference your system item numbers in their catalog content and pass back your system item numbers through punchout, so that your system item is part of your iProcurement requisition?

Can you maintain a supplier item number > buyer item number mapping in eCommerce Gateway, so that you can ultimately create an iProcurement requisition with punchout that has an Oracle system item number?

Has anyone done something like this?  Any high-level confirmation or guidance would be appreciated.  I am seeing buyerItemNumber within the punchout DTDs, and so I am somewhat hopeful that it can be used in the way I have described.