It never hurts to experiment but I do agree that the primary listening position should at least be your starting point.
I used the primary position for my calibrations but then used the advanced MCACC to compensate for standing waves at 3 points across my main couch. Note that you can only do the 3 point standing wave measurement if you go into the advanced MCACC and perform that specific calibration individually. Full auto mode will only use the one position.
Main thing is to experiment and do what sounds best to you. Have fun!