I find it incredible that anyone would consider adding the complexity, unreliability and weight of dual throttles or build a "Mr. Potato Head" panel based on the mistaken idea that one hand is always better at doing something than the other. People confuse dominance with ability. Think of your dominant side as being your default side. If someone chucks a rock at you, your central nervous system reacts reflexively to deflect the projectile with your default limb. There isn't time to decide between two possibilities so evolution has preferred that it is better to get the job done quickly than to consider the response and select an option.

The result of this is that the dominant hand is used more so it is better trained. Given a new task (move stick, drive plane) either hand has the same intrinsic capability and the brain will adapt accordingly.

Consider this, most string instruments require greater dexterity from the left hand. How about the piano? Driving a manual shifting automobile? This freaking keyboard?

If there was a measurable safety related phenomenon due to a preference to the "sinistra" then wouldn't insurance companies require you to disclose this and, more importantly, charge a little extra?

Try this. Take a piece of paper and two pens. Starting in the center of the page, write your signature with both hands simultaneously but write backwards with your non-dominant hand (mirror image). Compare your backwards signature (in a mirror) to your normal signature. Surprising how good your non default hand's penmanship is, isn't it? Even without practice.

Building a dual throttle is a really bad idea. Even Boeing knows this. Besides the mechanical issues of weight, friction and jamming you have the added possibility of the passenger having unfettered access. Bad enough I have to warn them off the stick every time their seat gets adjusted. People have reflexes (see above) and one of those reflexes is to grab on to the nearest object if they are jostled.

Keep it simple. Practice emergency procedures. Be safe.

I'd give my right arm to be ambidextrous.

Regards
Brent Regan