On my SC-05, the MCACC main measure does one position. The 3 position measurement comes from the standing wave correction. I had to go to the advanced measurements specifically for the standing wave portion and tell it to calibrate 3 positions. Otherwise it will just default to one. Not sure if the new incarnations of MCACC are the same.

Dan
On-Wall M5HP LCR, QS8 & EP500 in 7.1