I have a friend who teaches neuro-ophthalmology down the street at Midwestern U. and he would strongly disagree that "eye dominance is largely psychological". Please discuss with your eye professional.

Information from 2 optometrists who specialize in helping shotgunners

Dr. Barry Nolt on cross-firing and gun fit
https://www.drbarrynolt.com/shooting-glasses/shooting-articles-by-dr-nolt/why-did-i-miss/

Dr Richard Colo discussing eye dominance and clay target shooting



Gil Ash and Nick Penn demand 2 eyed shooting



You can draw your own conclusions regarding Ralph Cushman, author of "The Myth of Eye Dominance in Shotgunning and the Reality of the Subconscious Mind" that you linked
https://www.trapshooters.com/threads/full-n-fuller-credentials.909965/
https://www.trapshooters.com/threads/not-to-hijack-the-eye-dominance-thread.201625/
https://www.trapshooters.com/threads/eye-dominance-issue.914183/page-2
https://www.shotgunworld.com/threads/left-eye-dominant-shooter.540925/

Dave Carrie, a one eyed & accomplished shooter would disagree with all 3
https://www.davecarrieshooting.co.uk/

as do Ed Solomons and Ed Lyons
https://www.shotgunworld.com/threads/worried-about-closing-an-eye.543479/#post-4651525

as does Peter Blakeley
https://www.peteblakeley.com/wp-content/uploads/2022/01/pete-blakeley-one-eye-or-two.pdf
His discussion of shifting dominance which you'll need to cut and paste into a search as it would not link
https://sites.google.com/site/howspaceisperceived/a-practical-example?tmpl=%2FSsystem%2Fapp%2Ftemplates%2Fprint%2F&showPrintDialogue=1

as does Phil Kiner
https://www.trapshooters.com/threads/eye-dominance-issue.874677/page-4
"With all due respect those that think it is an issue of looking properly - YOU DON'T KNOW WHAT THE HELL YOU'RE TALKING ABOUT. PERIOD
If you DON'T have an issue with cross-firing you have no idea what it is like to have an issue and it is real and it is incontrollable and at this moment in time not curable."


There is some degree of dominance plasticity in the very young, which is the point of using an occlusive for amblyopia (lazy eye).
There are anecdotal reports of shooters claiming they can change dominance, and some who are cross-dominant have successfully competed with both eyes open, notably Brad Dysinger.