I finally received an answer from BA Highlife which, if nothing else, made me laugh! They said the reason there is no duty free deliveries on BA296 is because BA only flies to ORD for maintenance so there are no pax. You couldn’t make it up. Last time I had a Highlife problem BA customer services shrugged it iff and said they have no responsibility for Highlife. Clearly they are also not worried about the effect on their reputation.