Where should I mount the spare tire

I just purchased a Starcraft 26bhs this week and am having a receiver mounted on the back bumper for my bike rack, along w/ the bumper being reinforced. Its the same setup I had on the camper I just traded in. On that one I had them mount the spare under the tongue. On this TT since its a tad heavier than my old one by about 800lbs, I am getting close to max payload capacity judging by the dry hitch weight (around 550lbs)and what we carry w/ us (total weight how it sits now is 5200lbs). Would adding the spare on this tongue be a major issue or would it be better to mount it underneath or towards the rear? I do run a WDH so I am thinking although you may add 50lbs to the tongue, 1/3 of that is transfered back to the tt wheels once the wdh is adjusted, correct?

Since I will have a lot more storage in the front of this unit as well as at the back in the lower storage compartments, I will be able to shift and play w/ the load a bit to fine tune it and get the 12% or so I need in total weight over the tongue. I wont know till I get it on a scale but I need to get the spare mounted before I pick it up Friday. Based off of this limited info, what are your thoughts? This TT has the arctic package on it so I dont think there are many options underneath of it but have not looked too hard yet either. Thanks!!