I think what gus is saying is that as an mpl is only valid with a TR, then technically the TR you get during training for whatever aircraft you train on makes it valid. This is still very risky business though. The main thing we need answering to is how easy one can change from an mpl to a cpl/ir during training if they failed a part (btw i understand Qatar cadets must achieve a minimum of 85% throughout ground school). I have done some research and found out it has happened where a company called sterling air dropped mpl cadets before 1500 hrs (but they already had the TR with sterling air), they had to pay about 30000 for conversion