+1"I contend that both eyes should be open...keeping both open allows the eyes to relax, no mussel strain...I qualified Expert."
Very, very interesting. I am cross dominant also. I have traditionally been able to compensate with pistol shooting by simply turning my head about 15 degrees in order for my left dominant eye to take focus on the sights and keep both eyes open. It has become pretty natural for me at this point. Rifle shooting with open sights I must close my left eye. With optics, I found that both eyes open works fine. I have tried shooting lefty but after decades of compensating, it has proved an almost insurmountable challenge to relearn everything. Huge hat tip to you, and others who do the same, to be able to go through with it. I honestly don't know how you do it! I will admit that shooting with sights, my weak eye gets tired rapidly, and even does with optics but not as rapidly.I've transitioned to shooting lefty because of my cross dominance. Works better and does relieve eye strain.
Sound silly but I started brushing my teeth left handed to help develop fine motor skills