KEEP THE BODY HARNESS!

The chest straps are rib breakers and if you wear it on your waist, it'll snap your back in half when you fall. Many fall deaths involve the use or misuse of the chest straps. The full harnesses have decellerators built in to the lifeline that goes from the harness to the tree so you don't stop quite so suddenly. Chest straps don't have this feature.

The only safe way to use a chest strap in as a "positioning device" that, by definition, 'keeps you from falling'. This will not allow the freedom of movement required for effective treestand hunting.

You'll be in trouble pretty quick even if you have to hang in a full harness for very long, so have a plan for getting back into your stand, down the tree or whatever. I keep a knife handy to cut myself loose in case something gets tangled or I get pinned funny.

I recommend the SOP (Seat of the pants).

If you ever fall hard enough for the decellerator starts to unfold, get a new lifeline.