I have been meaning to post up this picture of my bungie mount on my P2. I use a single piece of bungie with a cord lock. What is hard to see is that at the end of the cord lock is a keeper ring. To put the computer on I make the loops as big as they go, slide it over my wrist. To snug it down I place computer face on my chest, pull the bungie tight, grab the keeper ring in my teeth, slide the cord lock down.
Note: to make this system work the cord lock needs to be on the battery side of the computer with the knot on the opposite. Hope the photo is clear enough.
View attachment 221578