Maybe I'm thinking too much as a former engineer, but given the complexities of these planes, wouldn't it have been better to START with the freighter version? If they would have built the freighter first they could have resolved the airframe issues, flight controls, flight testing, etc., then moved to add the more complex interior modules that account for a large part of their wiring issues.
The Freighter version first would have built confidence into the manufacturing process as it minimized overall exposure.
Oh well - never mind.