Originally Posted by
FBinNY
*That's good for setting the seat angle, but meaningless for the fore/aft adjustment.*
However, results rule. The right post is the one that gets the saddle where the OP needs it by calculation, rule of thumb or personal preference.
If either post can do that, the tie breaker would be factors like no-shim fit to the frame, weight, cosmetic, etc.
I use what might be described as "modern fit theory" which says that the proper position for a level saddle should be determined by how much weight is on one's hands. Usually that's done as the rider in the posted video demonstrates, starting at 5:50. The saddle should not be tilted either up or down.