I forgot to say in my last post that you could use autosuggestion. It helps me alot to wake up in the middle of the night and to remember dreams. So it can make you more aware when you wake up. Just repeat several times a mantra in your head (like "I wake up after my dreams" or "I stay still when I wake up") and really believe in that and try to imagine the feeling that, when you wake up, you dont move. Try to do that until you fall asleep (for better results). It may seem that it's not related to your problem but I believe that it will make you more aware of the times you wake up during the night (naturally), making you aware more easier when your alarm beeps.

PS: This can also aid you to do a normal DEILD without the alarm.