Large Document Handling for Attachments?

I have read over the material regarding large document handling for Trading Networks. However, is it possible to treat attachments received via Ariba OnRamp’s receiveCXML service in the same fashion? I haven’t seen any documentation about this, but it seems like that would be a very reasonable thing to want to be able to do. For our system we will be receiving potentially large attachments with PunchOutSetupRequests.