"I know nothing about the book but if you use the Step,Swing ,drift principle in the feather step you have to finish in the down position on the RF . To stay up on the toes is not the completion of the drift and therefor not the completion of the whole movement."
That is not the completion either, as you are by then starting to make a new swing.
See Douglass Adams...
If you want to find an ending - ie stop, you have to do an inefficient halfway rise - to the point where your motive energy has been converted/dissipated, but your feet are still flat on the ground. We see this in the hesitation figures... A prep step is the act of lowering from such a position to build up speed and begin the normal swing cycle.