I was trying to figure out how to secure my water bottle (an REI infuser) to a LCB, when I looked at the stuff sack I have for my down booties (feet always get cold when camping). I noticed that it had a clip on the side, kinda like a TB stuff sack. I attached it to an o-ring, and whalla! A secured spot to drop in my water bottle! Does it stand perfectly straight? No. But it does keep the bottle from tipping more than 30 degrees, or from wandering from one side of the bag to the other. Plus, it provides support for when the bag is mostly empty. Granted, I'm not using a TB stuff sack, but I'm sure they would work just as well. Hope this helps someone else!
Sack clipped to o-ring
Maximum tilt in bag