Hi Paul,
PI system needs to be used for many kinds of documents transfer, so even if you don't want to transfer contract via PI, it still can be used for other documents transfer.
For contract transfer, if you still want to use the old way to transfer it, you can set the system type in bbp_backend_dest for ECC system as ERP_3.0 or lower release so that it will read other program/ FM in table bbp_function_map.
Best regards,
Ivy