Very true...I was distracted writing that post. Of course weight makes a difference in that it will increase rolling resistance. My main thinking was accelerating the weight, not so much the effect the weight is going to have on the contact patch on the tires, which is also important.
In the end, t doesn't really change what I was trying to get at: that the higher recommended tire pressure on the Model 3 has a significant benefit to the highway efficiency of the car, in addition to the aerodynamics. Basically filling the tires to 45psi versus the LEAF's 35psi (or whatever, notwithstanding those of you that inflate to 44psi anyway) compensates for the additional weight of the battery (I guess we would work out exactly how much, but I've got too much going on right now!)