A group of 12 pilots from my company attended Air China screening. ALL had 'medical problems' including one guy being told he had a terminal heart defect.
Their colour blind test is a killer, for sure. Not Ishihara, but some weird kind of fractal chart test done in a darkened room under artificial light.
The Med Test facilities are stone age by the way. Cold dark corridoors filled with queue jumping locals.
The guy with the terminal heart problem rushed home to see a top heart specialist, and was told there was absolutely nothing wrong with his heart. Load of BS.
Don't go to China for screening if you aren't 18 and in peak physical condition. You'll fail, and your fail will cause problems for your renewal at home.
LoL Insurance will use it as an excuse not to pay if you lose your licence later. You know how Insurance companies work.
Besides all that - the screening is ass backward. They expect you to study for their ATPL exams and pass the test before you're even selected in the Sim or passed the Med.
With a 75% failure rate I shudder to think of the time wasted by so many ICAO ATPL qualified pilots who cram this crap into their brain only to wash out on a fictional Med issue.
This will all change as pilot surpluses dry up.
Stay away. Keep your powder dry.
If you apply now and fail on BS Med grounds you are finished forever.
The low-timers will take the jobs later, when sensible Med standards come in.
Good luck trying.