I accomplished the GCAA medical recently and found it quite easy in comparison to other Asian countries. The only blood test was to check your red blood cell count. The BMI was not looked at in depth like Japan or China. If you have a special issue medical just explain to the doctor your situation. They will most likely ask for further additional tests to verify the severity of your condition. Overall it was a positive experience and more of a common sense approach of trying to help you pass. In the end I chose to not pursue the job because of other issues in Dubai but I do recommend it for NTR pilots trying to move up the ladder as the ME offers opportunity albeit at a cost. I would apply and then cross the medical bridge when you come to it if you make it that far.