When I took White's summer program in the 60s I had read Adams and asked White what was the difference, from what I recall Pre Visualizing was prior to releasing the shutter, then the final print was visualized in the darkroom and post darkroom, toning. Not sure why he did not make that clear in his book. He might have given a different explanation to others as well.
AA wrote about shooting with Edward Weston, AA was using his zone system, EW would look at his Weston meter, mutter a bit then add 3 stops. What ever process EW used he worked for him. Remember that the majority of EW's work was contacted printed, his negatives would look very different from those of AA who projection printed with a diffusion enlarger.
Over the years the zone system got a bad rep, those who used the zone seemed to spend more time plotting curves than taking pictures, zone folks had their own special language, and seemed to have forgot that AA developed to enhance the creative process not to become a slave to the process. Other myths is that the zone system produced a perfect negative. In his book about the making of some his better know works AA gave the number of burns and dodges it took make "Storm Clearing." The negative was not perfect, it was workable.
Most photogpghers did not and do come from a painting background. I did not, I had to learn what painters seem to possess, the ability to see a composed image, without thinking about it. Shooting a news story, no issue, the action, the event, the person, the place or thing is the subject, shooting on the fly just get it in focus and in the frame, and with luck get the right moment. My wife can pick up a camera, look though the viewfinder and see the composition of the frame without thinking about it. She is a trained artist who before going to work as a journalist worked as a commercial artist. I have to think about it.