As Uncle Hank said:
"I don't see a recommendation as to the procedure the writer thinks should be used."

I'm all ears and would consider a different descent procedure, but I use a similar procedure as Hank and not cracked a cylinder in decades. That's how my father (Captain Fritz Compton / A&P) taught me in 1968 as well as advice from mechanics and engine overhaulers. Seems that the owner of the towplane has the final say.

So if "shock-cooling" is a myth, so be it. I'll stick to my descent procedure until convinced otherwise.
If I buy into that shock-cooling is a myth will the writer of the article pay for a cracked cylinder replacement? Give me a new procedure / reason to change!

A real concern for me is a potential midair with an aircraft below release altitude when aggressively diving the towplane down after release, so my towpilots make a slow descent, looking outside. What's the hurry? As my Dad (who flew the US Mail for Eastern Air Lines starting in 1939) said, "Take it slow son, we ain't flyin' the mail, just gliders."

Then again, y'all do what you want . . . my way isn't the only way.