I drilled and tapped a couple 1/4-20 on each side to mount golf cart mirrors. But for something like a cane I made a mount out of a 5" exhaust clamp that I welded a short piece of metal tubing on the saddle then slid in some pvc about 30" long. Clamping that to the round loader mount I carry and axe that is always handy on the left side. Sorry no picture right now. But the clamp size being 5" you could bolt a pvc cap of any suitable size to it and then add a cane length tube.I think this discussion is verging on paranoia. I see no risk of structural compromise from drilling a couple small screw holes in a loader frame.
Dan
Bill