Yes you can use live view but it's very important to set some Focus Time to prevent missed shots:
NMX: in the app navigate to 'Advanced Camera' and set Focus to at least 0.3 seconds (the default is 0.6)
MX3: in the settings area navigate to Camera>Focus and set to 300 mS or more.
What does this does is send a brief focus signal before the trigger signal. This is important in live view because a majority of cameras with live view enabled will display an 'auto review' image on the camera's screen for a few seconds after the exposure is complete. If the controller is trying to trigger the camera while the auto review image is displaying the camera will block the trigger signal! By setting the system to send a quick focus signal before the shutter signal this 'clears' the auto review and prepares the camera for another exposure signal.