Spark Plug temp sensors

[Czakky]

I've seen a few a/c bikes on the internet with these little thermistor rings on a little digital display to check head temp I guess.
Do any of you guys use them? Are they useful?

Example

https://www.denniskirk.com/trail-tech/orange-tto-digital-temperature-meter-m16x1-0-screw-sensor-743-es1.p4001096.prd/4001096.sku?utm_source=google&utm_medium=csecid=6821162156&aid=76472566741&keyword=830204666614%3A%3Apla-830204666614&kid=830204666614&gclid=CjwKCAjwr7X4BRA4EiwAUXjbtzB7fG7L-_fMwsc2ZGLvS-CkLeOxbS2Qgd9Kt_kAHAVn2ghpwRK4ABoCSHIQAvD_BwE

[1976RD400C]

I have those on my bike. You can watch and see how and when it is warmed up, compare the 2 cylinders that helps detect if something is wrong with one, and will at least give you a warning if the temp goes too high.

[Czakky]

Thanks for the input