And each to their own what works for them. I’m very dominant left handed, left eye.
All my bolt guns are lefties, and would never go back, but for ARs, and if upgrading parts, especially BCG etc, are on your upgrade list, then a right handed version is the only way to go.
As for ejection issues, I have several ARs, and owned others over the years, all righties, fried many thousands of rounds of 223/308 and now Creedmoor, and never had one issue firing them left handed, with right side ejection. So a non issue to me, and any other people I know and shoot with. Never even thought about powder burn-eye problems? I am reloading everything though, and others may have had issues with mil spec ammo and this is a known issue for it? Plus should always wear glasses and then no worries regardless.
I will say though, if the parts I wanted to upgrade my stag were available in left handed version, I’d have bought a leftie.
So no real wrong answer here, just what are your long term plans for it? If keeping it stock, then leftie is great, and if you plan on major upgrades in the future, right handed is definitely an easier route to take, and the right hand ejection will not be any impediment.