I'm in my mid 30's. I agree that switching younger is easier thanks to neural plasticity, but I don't see any reason why one could not switch later in life with the right attitude.
I agree with you that consistent form and shot execution is key to accuracy. The difference in my experience is how much mental bandwidth goes in to forcing your non-dominant eye to be the primary focus. It feels like constantly fighting your brain. Using my dominate eye felt like relieving a massive mental burden that I could apply to execution.
One could argue that many archers with the potential to become Olympic level never switched and fulfilled their potential. I would personally never have been able to shoot past 50 yards if I stayed with my right hand because I could not shrink my groups. Activating a release imo does not require a ton of dexterity, just consistency. If there was an Olympic sport of using chopsticks, then by all means...
In Korean (and Asian) culture, there is an old school stigma to being left handed. Often parents would forcibly change their children to become right handed. I think that often screws up a child's coordination because they are learning everything with the wrong side, even if they eventually become proficient. Then there is a matter of coaching. I guarantee every Olympic level coach in Korea is right handed, right eye dominate. Shooters are competing with the best of the best out there, so a cross eye dominate shooter just would not make the cut out there. Left handed shooters probably do not get the coaching or recognition early enough to become world class.
