I went that route for a while. Still do if I need to carry emergency supplies and a large water bladder. The taking it off and on and getting my stuff dirty got old. Instead I hang a call organizer from a binocular strap. It's the kind that crosses behind your back like, well like a sports bra. I hang a pad for my back off the back. Seat pad clips to my belt.
I don't recall the name, but I saw something similar to what I have rigged up in Midwest Turkey Call Supply.