Having seen some of Joel Turner's recent videos it seems he has a good grasp of the 'mental' side of shooting, at least with regard to controlling the shot. But, his videos suggest that routinely holding the bow at anchor for long periods of time (perhaps 7 to 11 seconds...just a rough estimate based on slow counting some of his shots between his anchor and release) is a key factor in shooting well. The concern here is that even if he doesn't intend it as a key factor (I.e., even if it's simply his own personal style, not necessarily part of his instruction) the casual observer might regard holding that long as part of the recommended instruction.
I think most experienced archers would not advocate routinely holding at anchor for as long as JT seems to do, as it might actually invite what we want to avoid...overthinking the shot and the potential for target panic. It also does not seem to be a practical approach for bows of heavier weights, such as those that make sense for hunting.
There may still be some chinks to work out in his presentations, or at least some further explanations of why he does what he does and what his key do's and don'ts are. But he's an interesting archer for sure.