Phallosan Forte can be worn while sleeping. It does not restrict blood flow in any way.
I also have worn a simple traction wrap (ace bandage) while sleeping. Don’t wrap too tight. You should know right away if you’ve done it too tight. If it’s too tight, re-wrap and try again. To be safe, just wear it for like an hour before you go to bed and monitor it to make sure it’s not constricting. Purple glans = bad. If everything is normal color and feels good after an hour, you can go ahead and sleep with it. Your dick will still be there in the morning.
The traction wrap might not necessarily “stretch” you but it will prevent you from turtling and keep you with a large flaccid while you sleep. The PF will definitely stretch. I’ve slept with mine a couple times recently. Both times I made it about 4-5 hours before I took it off when I got up to pee. It will take some getting used to if you like to roll around a lot and/or sleep on your stomach, but it’s doable.