Craig, I think you know the answers to your own questions. Most guns with double triggers are sxs. How many shooters today start out shooting sxs? If they start out shooting an OU, that's likely what they're going to continue to shoot.

As for one's rear hand . . . which hand guides the gun, Craig--front or rear? The rear hand is just along for the ride, and to pull the trigger. A very slight movement of the rear hand isn't likely to make much difference.

Let's face it . . . those of us hanging out on this BB are an anachronism. We're misplaced in time, by about a century. We should count ourselves lucky that we're not much worried about the influenza epidemic and don't have to worry about prohibition of alcohol in the near future.