George, I feel for ya bro ,I'm an L1 burst a year and a half out,and have been trying to figure a way to carry my "babies " in a chair for about a year.
I don't carry anything that big but I agree that appendix and cross draw don't work so well. I cant reach my ankles with all that wonderful titanium in there so I guess on the shoulder is all that's left. Gona suck in the summer tho.