Anonymous. When reading from a book one needs to be very catrefull.
When you wrote. " The Feather Step has a evolution of body position entirely absent from the isolation walk described in the book ". Alex Moore in the description of a Forward Walk in the front part of the book is describing any Forward Walk or any Backward Walk in the Waltz. Foxtrot , Quickstep or V. Waltz.
He expected a reader to be able to add to that CBM or CBMP plus Sway.
Correct me if I am wrong . Is there Sway on one Forward Walk. No there isn't. The Sway will be on the following step or steps. A typical example is the Feather Step. Which brings us to. Sway is used if there is a turn or a curve which there is on steps 2 and 3 of a Feather. It curves.
The lesson to be learnt here is read the book as it is written. What is written on page nine still applies right through the whole book. You will on page 205 for instance, not be sent back to page nine to confirm how a Forward Walk is supposed to be performed. You are supposed to know having read all of the book.