I have and use four different camp chairs, none of which I expect to be robust enough for you though are the lightest I have been able to find and deem suitable to carry backpacking.
Alite Monarch and Alite Mayfly.
The Mayfly is essentially a Monarch with the addition of a front leg. I rarely use that leg.
- It's very comfortable once in,
- Monarch is a balancing act to sit in but is surprisingly easy to manage. I sleep in it with no issue
- Low to the ground and a challenge to enter and exit.
- Not the lightest option but both found their way into my pack on many backpacking trips
I don't believe the Mayfly is available new, but you can find them on Marketplace occasionally.
The Helinox Chair Zero
I switched to the Chair Zero because:
- It sits higher than the Alite chairs and is far easier to get in and out, especially after a long day of hiking,
- Much more comfortable
- It is far lighter than the Alite chairs at just one pound
- Chair Zero high back is available too
The only negative I found is that the legs on the Chair Zero sink into all but the hardest ground and it fairly easy to tip. Some easy solutions to the sinking legs can be found on the web.
The Nemo Moonlite
I don't consider this a backpacking chair. It's a bit too heavy for my kit. I sat in one at Public Lands and fell in love. I use this when camping out of the Jeep.
- By far the most comfortable. Like head and shoulders more comfortable than all of the above.
- Tank-Built
- Higher than all of the above and easier to get in and out
- Legs don't sink into the ground.. ever. Seems like black-magic but the design of the rubber feet works on all but the absolute softest of sand
- Has recline capability which is rare for a chair this small. Seemed hokey at first, but does as advertised and I do use it often
- Not the lightest or cheapest
I have minor lower back issues.. nothing major, but after miles of hiking having a chair with back support is far better than sitting on the ground. Keeping my body warm is equally important. I have a quilted comforter that fits under all of the above. Weight is negligible but benefits are measurable. I believe it is an REI brand but can't find a link..