Ability to update ship method on transfer order/sales order(created through enrichment rules)

Summary:

Need the ability to update the ship method on the transfer order or sales order created from the transfer order using enrichment rules.

Content (please ensure you mask any confidential information):

Sales Representative would create a transfer order. When we create the TO, there is no option to add the ship method on the UI (Create Supply Request page when they are created from the Manage item Quantities UI). Neither is allowed to update on the sales order created using enrichment rules. The ship method on the SO is getting auto populated based on the sourcing rule defined.

Issue is that we cannot hardcode the ship method for any combination of warehouse/item, etc; It is decided by business (Sales representative) and needs to be populated on the transfer order/sales order. Based on the ship method that is on the transfer order/sales order, shipping is planned and the charges and other attributes get populated on custom attributes on order/shipment line. This OIC call to 3rd part transportation services is done just after pick release.