How exactly does the FBT work with the KINECT? is it something I have to side load with a third party app? obviously steam VR wouldn't just pick it up natively? 

Also I already have my two base stations that I've always used, can I use the stations and the kinect together for better tracking? or will the kinect just replace all the tracking? Ideally I just want my base stations to continue to track my upper body/arms/head movements and use kinect just to tracks legs and hips/turning motions. Any info is appreciated. The vive pucks are too damn expensive and I'm considering a kinect set up