Phil. If you are looking at the same clip I am looking at. I don't see any twisting of the spine at all. On the CBMP I see the right shoulder over the right hip. Spine straight. Could be you are missing the curve to the right on te Feather.
My experience is if the Feather is taken straight forward all sorts of problems will arise. Then another mistake on top of a mistake and so on. To carry on. If the right shoulder cannot stay over the right hip. ( no twisting ) Something is not right. I am sure if you look again you will see. Plus going into a neutral position on a count of and. Thats 4 and .
I've looked again. I can at no time see the whole of the right side not in line.Also look for the neutral position at the end of the Feather.
Once the sides are used correctly, and danced as a unit you might be suprised what a difference it makes to the Quickstep, if you have been twisting you top out of line.
To carry on. After the CBMP on the Feather. Just bring the right side around to the balance point. This includes your whole of your frame elbow to elbow Then forward LF with CBM. It will be intersting to see what you think.