I had also heard he was cross-dominant. I'm currently reading through The Modern Technique of the Pistol for the first time to trace the evolution of the modern technique as was suggested by another member. I find it laborious even though Cooper (as editor) and Morrison are good writers. Why? Because there is nothing new, the contents are shopworn. That, in and off itself is testimony as to the influence that Cooper had on the art and science of pistolcraft.
I would put forth that in my experience teaching DA revolver to the masses, grip/finger strength was more of an issue than anticipation, once you get them past staging the trigger.
Back then we probably inaccurately called the DA pull a gross motor movement and a SA press a fine motor movement.