I feel the following ideas should be added to the proposal for indicating the location of the body in the vertical dimension.

1. The zones, like the kinesphere, travel with you.
2. The zones are 3D and vary according to the height of the mover.
3. The zones only define the space in the upward/downward dimension; they do not define the space in the forward/backward, right/left dimensions.
4. The boundaries of the zones are not etched in stone. They are flexible and allow for some variation to reflect the intent of the movement.