I re-read OP's final question about "no effect on TW" and realized I was completely misunderstanding his question...or what he was trying to do. If he is wanting to know where to place individual items and how the placement affects TW, here is the formula.
The above is the only graphic I had...so pretend the Suburban is my AS. The rear axle is the point midway between the AS axles and the front axle of the Suburban is the tongue jack on the AS. I use tongue jack as that is where most folks weigh the TW....but realize that if you want actual TW, defined as the weight resting on the ball, you will have to do a bit more math.
Assume a dead flat surface and an absolute level AS.
CGA = Distance from placement of object from the midpoint between the AS axles (fulcrum in our discussion)
WB = distance from jack to fulcrum
CGA divided by WB X100% = Percentage of weight of object on the jack
As an example with My AS:
WB = 214"
If I place a 150 pound object 24" in front of the fulcrum:
(24 divided by 214) X 100 = 11.2% is added to jack and 88.8 % is added to fulcrum..or 16.8 lb to jack; 133.2 lb to fulcrum
If I place a 150 pound object at the fulcrum:
(0 divided by 214) X 100 = 0% is added to jack and 100% is added to fulcrum..or 150 lb added to fulcrum and 0 lb added to jack
If I place a 150 pound object in the AS trunk 96" behind the fulcrum:
(-96 divided by 214) X 100 = -44.9% off the jack and 144.9% is added to fulcrum...or 67.4 lb REMOVED from jack and 217.4 lb added to fulcrum.
Maybe that's what you were looking for or maybe not??????