Years ago I always shot with my left eye closed (RH). My right eye is dominant, but barely. I was gap shooting at that time and doing lots of tournament shooting. The system really worked and I picked up my share of wins with the system I used.
Over the years I switched to a higher anchor point, both eyes open, and split vision vs a gap. The arrow is a blur and my aim is more of an arc estimation/feel than an "aim."
While I shoot about the same as I did back then, both eyes open feels more natural to me. In certain light situations, I still have to just squint that left eye a bit or I'm not seeing the arrow at all, which never worked too well for me.
Net, if shooting one eye closed works better, by all means, do it.