For the kettle I generally prefer a remote therm or a long stemmed therm I can poke thru the vent.
But once you get a few cooks going your lid mounted therm will indicate where you're at, even though it's not giving you an accurate grate level reading, for instance.
Just googled tel tru. Found a best price of 18.00. To my door 24.95.
This was just too clean and simple not to do it. People might think its dumb, but now I'll have some sort of heat reference. To each his own.