I subscribe to Erik's channel, respect and enjoy his content and have learned a great deal from him. I am familiar with Alex Wheeler but have not followed his channel. I am not aware of any statistically valid testing that Erik has proffered on his channel regarding seating depth. I do know that Keith Glasscock, also F-class, now PRS shooter was in the same camp as Erik regarding seating depth tuning...until three months ago when he tested his setting depth tuning with statistically valid sample sizes. He concluded there was no difference in accuracy between his "best" tuned seating depth and his "worst" tuned seating depth. I don't question Erik's abilities or success. I am just not sure they are for the reasons suggested. Based on Keith's data, Erik may have gotten the same scores using his worst tuned load. Only way to know is to get Erik to repeat the test that Keith did. Keith also shoots Bergers, but for some reason I thought Erik was sponsored by Lapua and shooting their brass and bullets?
What you are presenting is anecdotal evidence and what I am looking for is empirical evidence. I am new (since 2019) to the long range shooting community and admittedly my experience is limited. I have been frustrated with so many voices claiming their methods are "how it should be done" without any empirical evidence. I am not inferring that their methods don't work, what I am saying is that if so many different methods all produce the same results, accurate loads, then logically not all of the processes in the various methods are as significant as believed. In otherwords, their methods may work, but not for the reasons they think. My goal is, through empirical evidence, to sort out what actually makes a difference in the reloading process and what is just the deeply held dogma of the community.
So far, the empirical evidence I have seen supports the hypothesis that velocity and seating depth nodes are deeply held dogma, rather than something that actually makes a difference in the accuracy of a load. If there is some empirical evidence to the contrary I would love to see it, but at this point in my search for the truth, anecdotal evidence isn't going to sway me anymore than "because I said so".
And just to be clear, I deeply appreciate and respect the experience and knowledge of those in this community, and their willingness to share it. I know that their methods work and produce accurate results, all I am trying to do is figure out why.