Trying a tobii 4C at present.
The head tracking is too erratic for practical use. Even taking care with head movement and limiting angle in settings, the camera often pitches down or up.
Trying to land a plane when suddenly you're staring at the floor or ceiling is not pleasant.
The settings do expose an option to enable or disable head tracking. However if head tracking is disabled, eye tracking appears to be disabled as well.
I need a safe way to pan mostly left and right, and a little up and down, without erratic movement.