"He is always studying and evolving his technique to help with TP."
That puts me off a little bit. There is this German golfer, Langer, who was a stud on the PGA tour, but had a lot of problems with the yipps their version of TP. He wrote a whole book on how he cured himself after his first two bouts, and then he crashed and burned again. It actually isn't that complicated, and no doubt new stuff is being learned all the time, but there are also lots of people who seem set on a loosing path.
----------------------------------
Without a doubt I would look at Len Cardinal, he has it down. I wouldn't look at Masters of the Bare Bow 3, that tape has a ton of problems in it. That series is always interesting (I am only up to 4), but it fundamentally lacks a clue.
The best general archery instruction is in the Robin Hood vids, but you have to scratch around and sorta know what you are trying to compile. I got my eureka moment from them when I realize that Jay Barrs, Randy Ulmer, and Howard Hill all had the same fundamentals and not all the other guys on the series were the same, well none actually.
The Len TP Video is solid, but it is basically a VHS era video that captures his lecture using posters on an easel. And that is fine with me, but you have to have the kind of temperament where the lack of state of the art graphics and personalities doesn't bring your uptake to a complete halt. Technically, this is instruction from before Trad archery was a thing. But then that is the point. We had the solutions a long time ago. People who think the solutions are new may be a little behind the curve.
---------------------------------------
Another fun thing, if you have the interest, is to look at how sports like Position shooting, golf, etc... deal with similar issues. Golf in particular had some massive misconceptions on putting, at least up till around 2002, when I stopped studying the subject after I was hit by a plane, and haven't competed in anything since.