How is the shipping rate calculated for orders involving several sources?

How is the shipping rate calculated for orders involving several sources?

The Advanced MSI module has the option to automatically apply all relevant shipping rates and add them to the order total as shipping cost. Even though the shipping rate will show as a single value on the checkout, it will consist - one way or another - of shipping rates from all sources involved in the order. 

This is best demonstrated with two sources that have custom shipping rates set. For example, Berlin Warehouse: 



London Warehouse:



The Best Way shipment method is calculated based on the farther source location (Berlin in this example): 



The Flat Rate option is a sum of the custom flat rates for both sources: 



For such delivery methods as FedEx, UPS, USPS, etc., the shipping rate will be calculated according to their own logic: