I can't say I've built a hang-on stand, but me and my cousin have built multiple box stands for gun hunting. I do, however have a couple of the small Gorilla hang-ons and the platforms are tiny so recently I put a peice of plywood over them and added support along the edges. Their pretty heavy but luckily I drive the 4 wheeler up to the tree I plan to hang it on so it won't be too bad. Ill try to get pics up soon.
You can take my gun, from my cold dead hands.