The answer is actually the OG* when it comes to thermocouples, pre-dating bean temperature in most manufacturers, and that is the exhaust temperature.Though it goes by many names (exhaust temperature, return-air-temperature, environmental temperature, etc) it represents a measurement taken of the heat energy in the flow of air exiting the roasting chamber.
It is a major focus because thinking about what is happening to our coffee is the most important thing.
Built into that however, is the somewhat erroneous concept that the bean temperature thermocouple is an accurate measurement or representation of what is Depending on batch size, thermocouple placement, thickness, and type, we could be seeing a wide range of variation in readout of the bean temp thermocouple.
Because of this, focusing exclusively on the bean thermocouple temperature as if holy writ, keeps us from observing what is happening holistically in the roaster.
Certainly your chances improve if you put yourself in the company of others who also care enough about their happiness to admit “their way” isn’t working and invest in their future relationship success. If you are a mature, accomplished, single person seeking a lasting relationship.
And you can get yourself into the company of others with the same goal, you will not be single for long.