B2B Make vs Buy for Same Item and Organization

We have a customer requirement in Order Management / Global Order Promising where the same item and the same ship-from organization can be fulfilled with Back-to-Back Make or Back-to-Back Buy, based on a manual decision made by the Order Specialist user on the sales order line.

The current setup would use a Local Sourcing Rule to create by default the "B2B Buy" for the Item + Organization, for example Buy From Supplier X

When the Supply Request is created the fulfilment line will pass as the "Supply Type" equal to Buy (based on the sourcing rule).

However it can be created a rule, into the task