We would like to create a route with the following steps:

1. Picking (Warehouse/Stock -> Warehouse/Output)

2. Transit (Warehouse/Output -> Partner Locations/Delivery Company: Transit Location)

3. Delivery (Partner Locations/Delivery Company: Transit Location -> Partner Locations/Customers)

Based on our experience, Odoo is always assigning the delivery carrier information (stock.picking.carrier_id) on the step ending up at Partner Locations/Customers.

However, we would like to add the delivery carrier information on the transit step, in order to generate shipping labels. The goal is to validate the last delivery step only when the delivery has been confirmed.

How can we set up our route to assign the delivery carrier information on step 2?