I have had a 285/70R17, 255/80R17, and now a 245/70R19.5 in the OEM location with a hellwig sway-bar, larger than OEM Class V 2.5" receiver, and a mag-hytec diff cover. It's tight, but it does fit with careful attention when tightening it up. The tire has to go in at an angle, and then get pulled up with help. It's something you can do yourself. You might have to hold it aft with a ratchet strap if you have a diff cover.
I would try again and see, I don't see the superhitch being any narrower than the biggun I have. The hitch isn't even in the way.
I wouldn't put a tire on the front, I have had stuff in front of my Dodge and it DOES have an effect on temps. The OEM gauges didn't show it, but the OBDII reader and exhaust temp gauge did, not worth it when it should fit in the OEM place.
I also wouldn't want 100lbs in front of the axle up high, the FAW is close enough to the FAWR.