I am not able to get the Sensor 6 daughterboard to work. I spent way too long on this, but I finally figured out the problem: the daughter board PCB has a flaw! Look closely at these photos:
If you don't see it, I can understand. It took me forever too. But look closely at the ground (GND) pin for the inter-board connector. You will see that it is not connected to the copper fill on either side. I have confirmed this by doing a continuity check between the GND pad and the C1 pad that's supposed to be connected to ground (the Vcc side does have continuity to Vcc).
So how do we get this fixed? As it stands, this sensor cannot fly because, plainly, it's broken.