I'm left eye dominant, right handed, but I shoot lefty. I have and shoot unsingle, o/u, sbt, and top single. I shoot them all lefty with both eyes open. I don't think it really matters it's all in your head. Mike.
Iboh. you can shoot your preference with no regard to your eye dominance. Make you decision based on how you feel about the gun and bbl. Unsingles have a bit of lessened recoil advantage. Buy a .740 bore (or near .740)
Look into a new CG. It will have options and solutions for most trap related issues.