I have seen people put a clouded tape just at the point they would look through the lens when they have their head down on the stock. When they raise their head as to wait their turn the dot is above the eye and they see with the left eye.
Being left handed and left eye dominant, but shooting right handed with both eyes open, I think I have a good answer for this.
One, have the discipline to LOOK AT THE TARGET. My pre-shot focal point is at a distance. When I see the flash of the bird, I am not likely to bring focus all the way back to the gun, after locking on the target. I simply know better, and so do you.
Two, a high shooting gun helps to look over the gun instead at the gun. My Sporter/Skeet guns shoot around 80% high, The Trap gun shoots about 100% high. With focus on the target, if I have to cover the bird with the muzzle, one eye usually still sees the bird.
Works for me, YMMV.
These days, my left eye is so much stronger than my right eye, if I close or block it, I am impaired on the line. No, although I CAN shoot left handed, after 53 years, I am not going to change over to please anyone. I have finally got the gun fit I want.
The three Brownings I now shoot are right handed guns, in operation as well as fit. I am very happy with them, and after shooting and owning most brands, including the "K" and "P" guns, they are my brand of choice.
These days, having outlived my family and two wives, I only have to please myself. LOL
Ummm, this is not the original poster's gun...if you look at the post again, he is referencing a GunBroker ad and seemed to have created the title of the thread in jest.
When I saw the picture of this gun and rib, my first thought was not about eye dominance (although that may be why it was created) but more of a very right handed shooter who lost vision in their right eye.
I have a friend with this situation and he has tried cross-over stocks, attachable off-set sites (same concept as this rib but much smaller and attachable to a standard barrel), and shooting left handed.
This friend of mine was a very good shooter and he still amazes me with what he can do with little to no center vision in his right eye.
A handicapped shooter here in SOCAL has a similar problem, but he is blind in his right eye, and his rib has extensions to let his left eye sight on the bird...damn good shooter, and from a rolling chair to boot!...He breaks 'em with the best !....LarryB