I don't think shock cooling induced
damage is a myth but clearly there are so many variations in operating conditions.
For example my cruise CHTs are around 370F, and I can get the EDM700 rapid cooling alarm very easily, simply by enriching the mixture a bit too quickly. I also have to work hard to keep CHTs below 400F; have to trim to 120kt
ASAP after takeoff and even then it is close. On a hot day they touch 420F.
Clearly my TB20 engine is very differently cowled to Englishal's Commander 112 engine.
I can't install a CHT probe in the present aircraft because it's "club "aircraft.
If you cannot persuade them to install a simple and cheap gauge which might make their engine last longer, then you don't need to worry if it doesn't
