I may be over-thinking this issue but I'm a little confused by what happens to the design CG when I move the tank. You adjust location of weights with an empty tank to get to the point designated. Now, with a forward tank, this location presumably takes into account the effect on the flight CG of some percentage of the fuel in the tank. In other words, the designated location would be aft of the desired flight CG. It seems to me that with the tank "on the CG", you would end up being tail heavy if you balanced at the design point. For those who have moved the tank to the CG, where is the new balance point?