I did see that the gaze cursor is visible as a dot in PE and it can be used to select items when no controllers or hands are available. You could use the volume buttons to confirm the selection which would mean that you just your HMD to use PiTool.
Regarding dual hand and controller interactions there is the issue of which hand / controller takes precedence. I suggest the hand / controller that is closest to the gaze cursor takes precedence.
When eye-tracking is available you can use a dynamic gaze cursor instead of the static one.
Are gamepads already supported?