I don't mean this to be argumentative, but I really don't understand the big deal about pre-flash. I mean, I understand that a bright pre-flash would cause you're night vision to suffer if your eyes are already adjusted to complete darkness, and I can see where the pre-flash could bother someone else. The thing is, the pre-flash lasts how long? Milliseconds? Just cover the bezel with your hand for that amount of time. If you can't use two hands, hold the bezel down onto something like covers on your bed, or against your stomach and turn it on. If no one else is around, hold the light with your arm straight down by your waist with the bezel end facing behind you and turn it on.
If you're in a situation where you don't want to give away your location, well, if I were in a situation where I didn't want to give away my location, I wouldn't use a light at all. Again, I'm not trying to argue, I'm trying to understand. Would the previously mentioned suggestions not work? Are there other problems that I'm not considering? Pre-flash doesn't bother me, so it's hard for me to understand the problems it causes, especially problems that the previous suggestions don't cover.