Hi, I bought the QWIIC Boost board to be part of a project that utitlizes some Adafruit STEMMA/QT* Parts, which most of the system runs on 3.3V except with a temperature sensor that requires 5V for it’s I2C connections. How should the QWIIC Boost Board be connected to the QWIIC-STEMMA BUS? Is it Daisy chained, or is it like the demo picture with the Sparkfun BlackBoard C3?
Wire it like the picture/demo with the Blackboard C 
So the sensor would have to be soldered directly to the pads? Also, does any thing ever get connected to the PWR connector?
It’s Qwiic, so no soldering is needed. Just plug it in.
Actually, I take that back. The sockets on the qwiic boost are both 3.3 volts. If you want access to the 5 volts it provides, you will need to solder wires or headers to the 5V and GND terminals provided on the board.