Compass Auto Detection

So I understand that Pixhawk will auto detect when a 3DR GPS/Compass (and compatible devices) are connected.

In the Compass Calibration in MP, Pixhawk is selected, and no Manual Orientation settings are entered.

I do believe that the compass is located underneath the printed circuit board of the 3DR, in other words “upside down”. In a non-Pixhawk application (such as APM) that does not auto detect, one could assume that the 180 degree roll orientation would need to be set to 1.

My question is:
I connect the compass to Pixhawk, and perform the calibration. When I look at the Full Parameter list, I see the fields for COMPASS_EXTERNAL and COMPASS_ORIENT remain at 0. Should these values not change to 1 if the Pixhawk auto detected the compass? Or does Pixhawk detect it, but the values are not necessarily updated in Arducopter?