Configure Punchout with Supplier with 2 CPA without mapping in the Payload

Summary: We have a requirement to configured a punchout with a supplier that has 2 CPA without including the CPA number in the payload.

There is a new functionality that we can include the CPA as part of the payload, but the supplier said that there is a lot of problem changing the payload code.

This supplier has 2 CPS, depends on the item it should be associated with a different CPA.

Is there any other way that we can default the correct CPA without including that in the payload.

We are not using item (item master). we are using description.

Content (please ensure you mask any confidential information):