Since there is no standard location on our motors to measure temperature, no one publishes that type of data.
You may have your favorite spot, but it may be different from mine.
I used to run a Spektrum TM1000 with the temperature probe wrapped around the cylinder just under the header.
Then I read an old article that stated the guys running control-line speed (using .35 & .45 engines) for their record setting speed runs measured the temperature at the base of the glowplug and tuned for peak temperature.
When I moved the TM1000 sensor to the top, the temperature went up by 50*F.
The CSM "CarbSmart" uses a thermally conductive 2-part epoxy to bond their sensor to the fin closest to the glowplug and stated that was the most sensitive and accurate location
The CarbSmart adjusts the mixture base on the temperature changes from the sensor and is supposed to save fuel and protect the engine from lean conditions.
Mine never worked too well.
I get what you are asking.
But I don't have an answer for you.
The good news is most motors don't require "break in" anymore.
Personally, I will set the needles to the factory recommended settings and add 1/4 turn. Then fly it and lean it a maximum of 3 clicks before flying it again.
Believe 1/2 of what you see and none of what you hear.
Fake News will be the downfall of our Republic!