BPF:-
The Canadian Air Cadet aircraft are civil registered and maintained in accordance with the requirements of the Canadian Aviation Regulations.
Then you have answered your own question, BPF, as to why British Air Cadets cannot share the gliding experiences of Canadian cadets. The latter are regulated by a competent Air Regulator, the former are not. It would seem to me that the quickest solution would be for the British ACO to adopt the Canadian model, for the MAA will be unable to fulfil its purpose until it be made independent of the MOD and able at last to begin proper reform of British Military Airworthiness. Ditto British Military Air Accident Investigation.