OK, while we're on about readbacks, why, when I check in with Nowheresville Approach with 'Nowheresville - Airline 123, Boeing 7blah with information X Qnh 1003' does the ATC come back with 'Airline 123 - Nowheresville, information X Qnh 1003'. I know - I've just told you that! If there's a change then by all means say, and thank you for doing so, but, like these stupid frequencies, we're wasting valuable air-time and breath.
QNH is recorded on the flightdeck from arrival or departure ATIS. It can be confirmed on arrival and cross-checked when clearance is given to descend an altitude - and on departure with it can be given with taxi clearance. I see no other requirement to mention it unless it changes.