I know REM periods are supposed to get longer and longer as the morning goes on... however, I think early REM periods may be easier to maintain then the later ones, even if they are shorter. This might help those who's lucids seem to end right after they begin. It's also a good way to practice WILDs/FILDs. Any sort of induced lucid that is the first dream from the waking state. This doesn't really apply to DILDs because those can happen at any time.

My reason is think about it like this, after sleeping a certain amount of time:

3-4 hours: You should still be very tired. Your body still wants sleep, there's no denying that. If you go lucid during this time, I would think that it would to maintain lucidity, simply because your body has intention to stay asleep for another few hours. One WILD I recall, I felt so into the dream. To even test it out, I got myself excited, felt myself breathing rapidly, but the dream environment stayed completely stable. My longer lucids, which seem up to 5-15 minutes estimated real time, have taken place at this time.

7+ hours: Your body has already recieved a sufficient night's sleep. You've gone through a few REMs by now, and most likely, you'll be at a light sleep stage. Things like mild excitement, or small noises from the real world environment might be enough to end a lucid, or cause you to wake up from a non-lucid. For me, at this point, the average lucid seems to be 1-5 minutes long estimated real time. Big difference for me.

I know all REMs technically count as Stage 1 sleep, however, I believe there is a huge difference between how deep into the sleep you are in the early morning REMs over the late morning ones. And you might just end up having longer real time lucid dreams early on, then later on when you are really are on the border of sleep and awake.