There have been a couple requests for a write up, but I never did one. A picture is worth 1000 words. I took advantage of the offset of the carrier and added a little more to the bumper which allows the jerry cans to sit inside between the tire and tailgate.
I have to question the pole. I can tell from the images that it is thick walled tube, but I can also clearly see that its flexing with the weight of the tire in two different pics.
Had you considered using the tub mounting with pinch plates like the original Nissan design employed? I know you wanted to mount jerry cans behind it, but that may have still been achievable by extending the brackets out a bit from the tub. Usually I try not to criticize other peoples fab work because I don't do my own fab work, but the only weak point I see is that tube. Maybe use a cap that mounts to the top of the pole and secures it to the tub and eliminate the bend? I dunno.