If the rig can be modded to where the seat is at 90* from the back, and can be used as a "shelf", I could see this being an ideal setup for what we do. One of my big issues with carrying saddle, platform, climbing method, camera gear, hunting accessories, is the profile of the pack needed to do it. I've gotten it fairly small, but I hate having my goofy shape in the tree, and a big giant wart on the tree from the pack.
I've got a GW and it actually does shrink the size of the pack I use when I use it, because of the ability to stuff things between seat and back folded up. I'm sure this is just in my head, but it makes me feel better not contending with a big pack in the tree.
Last season on my first set on out of state hunt, I decided to overcome this by leaving camera bag and stepps bag at the base of the tree. I had a nice 8 walk in on the wrong trail on my weak side and get about 3 yards from tree. His eyes caught the bags, and he froze. I'll never know if he smelled or saw them first, but not getting a shot on him will forever stop me from leaving anything at base of tree.
To the OP - do you see a way you can use some straps or rope to use it sort of like a frame pack? How deep is that seat?