I saw few “carryalls” on different sites that hook up to a sleeve hitch, and liked the concept for getting wood up the hill without high lifting and having good maneuverability in the woods. I built mine with an angle iron and T-iron frame (from a free garage door opener). I bolted ¾ inch plywood to the frame. I was very concerned about breaking my cast lift arm so decided to suspend the sleeve hitch with chains by adding a piece of T-iron in my tool box. The thing works great for getting those large rounds of elm up to where you can get at them with a splitter. The weight limitation for the carryall is determined by the front wheels coming off the ground and loss of maneuverability.
My 122 has fluid in the tires and wheel weights so no problems climbing any grade.