I suppose the question is 'if' you are exempted from the requirement to hold a medical 'certificate' are you still exempt from notifying the governing agency of any medical conditions. As with the conditions of disclosure attached to a drivers licence. Then if you are truly self certifying and something should go wrong, how well are you protected legally without an agency having approved your condition. I would suggest it would be an answer very similar to the car driving legalities. The later answers can really only be tested in court if somebody is injured and your 'condition' or 'fitness' were to be questioned.