I work in Logistics so trust me freight doesn't give a damn where it flies from. We use Airlines based on their rates and services gone are the days which airport it flew from in the UK is a major factor.
People would switch freight from EK to QR based on the deal they are given, not the fact they fly from EDI.
Edinburgh may well have a great distribution system Joe, but then again so do most of the airports the MEB3 fly from.