Hey folks, author of the article here. Thanks for sharing and taking the time to read my work!
I'm here to answer some of your questions.
That's interesting that they would see POI shifts. It makes me wonder if they are stressing the rifle stock and action, or if the barrels weren't properly free-floated. I shoot with my bipod preloaded in F-Class competitions, but it's designed for PRS. It was good enough for me to earn my NRA Highmaster classification at 600yd. If preloading the bipod like that created massive POI shifts, I don't think it would be possible to get good scores.
That's an interesting suggestion. For the rifle I used, that would have taken a really long time. In order to use the F-Class front rest, I had to unscrew the front rail that my bipod attaches to.
Why do you think variances in the chrono or barrel lead to only 2 of the 20 rounds to be outside the norm?