I could see how you could get a lower LOT from sleeping on your stomach if your penis was pointed down, towards your feet, as you slept. That would put the ligs in a sort of long low intensity stretch for hours at a time. Over the course of years, it might stretch out the ligs enough to give you a lower LOT. It might be intensified when you get a boner while sleeping, which supposedly happens several times a night.
Having said that, I’ve been sleeping on my stomach probably 50 percent of the time for as long as I can remember and my LOT is still at about 10:30. So, never mind. Although, maybe I’d be at 11 or 12 if I slept on my back.(?)