I have a few of the HS210's and they all run like you said, about 95 degrees whether they are on or off. The Kasa dimmers and the regular switches all run cool.

I have all tp link smart switches, 2 way, dimmer, and 3 way. The 3 ways run about 95° whether they are on or off. They are the closest of all of them to the router. Both switches are controlling LED...