Instead of disabling positional tracking you can also recenter the head tracking (from the vorpX menu or with ALT+SPACE). That will reset the camera position to where it is normally without losing positinal tracking.
Binding ALT+SPACE to one of the controller buttons should do the trick. I would’t really waste a controller button for that though. There is a ‘Center Tracking’ button on the main page of the vorpX ingame menu. Since normally you won’t really have to reset the tracking very often, that makes more sense than using a dedicated controller button.