Update Purchase Orders as a customer in Responsive Replenishment

Hi all,

I am trying to understand the Responsive Replenishment process a bit better. As I understand it from the SAP documentation Replenishment Planning is done based on inventory and forecast (incl. promotions) in SNC on the vendor side. As a result TLB proposes Replenishment Orders that is send to the customer back end (PO) and to vendor back end (SO). I also saw that it is possible to change/confirm the sales order in the vendor system which would update RO and PO. Is it also possible for the customer to change or reject an order that was created by the vendor? If so, how is that done?

And one additional question on this matter: is the customer granted access to the SNC WebInterface in the RR scenario? I not seen any indication of that in the SAP documentation.

Thanks!