I could be wrong, but my understanding is that you want it as level as possible otherwise you can upset the handling and braking, especially on hard braking. You can't rely on your TT brakes being 100% effective, 100% of the time and that could potentially be a lot of additional weight pushing the TV forward.
You should easily be able to level out that 2" difference by adjusting the ball height, hitch head angle and/or the number of chain links. I just went through the process with our new TT on the way home from our dealer and it took 1-2 hours raising/lowering the ball height and adjusting the bar angle and finally ended up about 1/2" high on the nose. I couldn't seem to get it closer than 1/2" high or low so went with being slightly on the high side to account for weight added to the TT when all loaded up. The prevailing wisdom is to run slightly nose down to level when all loaded up and mods done.
The hardest part was finding a fairly flat parking lot where I wouldn't get in anyone's way for that long.