IMHO the right-hand/left-eye combination has an ADVANTAGE.
From the Weaver hold, extend your right arm some, and your right bicep becomes a perfect "cheekrest" for accurate fire. For faster/closer work, bend both elbows and twist the gun to the left to maintain left eye sight alignment as you bring your head vertical.
For Iscoseles shooters, there's no upside OR downside for cross-dominant shooting. It's in the Weaver where things get VERY cool.