It's an interesting read
however, a number of things have changed over time. One thing I noticed I've never seen anyone do is to position their rifle with the stock midway between the front of the stock and the action. Might be worth a try and the hard bags, that's conflicting what others preach. Both mine are as hard as I can get them. If the rear bag is soft, the rifle continues to sink with every shot. My font bag is as hard as a rock yet it is filled with sand. Also, not having his rifle restrained on the sides was interesting.
Another real big item is Benches. Most places one shoots benches move and in some places, A LOT! So, many things fight us in the quest of accuracy. I do think if they had weighed powder charges precisely, their groups would have gotten smaller than they were and from my 20 odd years of shooting and testing, I know powder matters as much as seating depth. Also thought it interesting they never got good group from jumping bullets. It seems to me they "settled" at some point, which many people do. I never have. I do agree with him on not using cronos. I have one but quit using it many years ago because for what we do, the information is useless. If bullets go into one tiny hole I don't care, within reason, how fast or how erratic the speed was. I know there are some lovely nodes way down low that in any wind at all, they are useless and as one goes up, the nodes get narrower or accuracy within them get narrower or spikey. .200" groups still win matches.