I cannot speak to the Roku but the 4th Gen Apple TV as well as the 4K Apple TV support both IR and RF. In my setup I have the 4K version and the Harmony controls it just fine using IR and using the Apple remote the RF works great.

The model I have is the Harmony Hub I believe. It’s the little puck thing which comes with a simple remote as well as app for Android, Apple, etc. It also integrates with Alexa and possibly others so using it is pretty darn easy.