vendor partner functions in SRM ECS

does the vendor partner functions OA, PI available in the PO transferred to the backend from SRM in ECS.

can we just replicate the OA partner function vendors into SRM ECS and create orders? does this have any issues while replicating to backend. if at all we decided to use only VN partner function vendor to create a PO in SRM, when it replicates to backend how the system identifies the invoicing party address for a vendor with out partner functions available in backend PO in srm ECS.

regards

deepu