That is EXACTLY where my thermostat probe is placed. I tried several locations and this location got my cage dialed in perfectly.
If you can, mount your RHP in your enclosure and plug it straight into the wall for a few days before setting it up for your snakes. Mine had some funky outgassing and burn off that I really didn’t want my snake to endure.
Good to hear I'm not the only one with the thermostat in this placement. As you can see from the picture, my little Boa loves 'sunning' under the RHP on his tree formation.