If you get a chance, please test this again with version 3.8.31 as you should see the touch action now, and you can long press the right icon in the quick action box to assign it to "Enable/disable face gestures" if that is your preference. The long press for that icon reassigns the action, so I can't use it to take you to the settings page. Once I add more configuration for the quick action box, then more options will be available for things like this.
Mike
Mike