Fraser, that's almost an impossible question to answer as quite often each case is taken on its own merits. What I suggest you do is make sure that your family GP is on board and answers any questions that the air force medics at OASC might ask of him 'to your advantage' - you need to brief him on the situation and then prime him with what you need him to say. No guarantees of course and you need to have a pretty good relationship with your GP (it worked for a friend of mine recently).
However, don't let it put you off applying - go for it!
Foldie