We have add many inquiries on tracking different parts of the Body, and you were right to ask : it is very important to have a feeling of your all body in VR for better immersion and to avoid motion sickness.
In this video you will see a very simple example showing how to use 5 Trackers to track your hands and feet position and orientation. In this setup we were using 8 Cameras and the Oculus, though the Camera were not oriented well to see the feet, so it could be improved.
You can find everything to do the same in our Examples.
You could improve this example by using a Invert Kinematic plugin to infer the legs, knees, arms positions depending on the hands and feet positions and rotations, and therefore show the full body in VR ! They are many plugin on Unity Asset Store to easily to such things.
Note that in a multiplayer environnement using that many Tag per User can limit your maximal number of user, to solve that issue we are working on a second way to do Body Tracking using IMUs.