Nowhere near an SME, sample size of one.
For many years, I thought I was a "pretty good" match shooter, who "didn't feel" match pressure. When I got into 911, I went from daily training and weekly practice to...well, nothing. Matches only. My scores went up, by a nontrivial margin (about a full class). I found it a lot easier to execute fundamentals.
I don't think that there's an ethical thing you can do on the range that truly duplicates consequence. I think your only two paths to attacking it are extreme repetition--training until it's impossible to do it any other way, which is out of reach of most people--or combining PT with practice to simulate the physiological (not mental) symptoms of stress.