"Suomynona. If I do a Feather Step with a slight curve,with CBMP making sure that I do start diagonal to centre. Doesn't that give me a more sweeping turn into the Reverse. Must not forget to get that heel of the LF off the floor as I step to the side on step two."
Please specify what you mean by stepping "to the side" on step 2 (the step is forwards with respect to your feet, which is what counts). Please note that if you curve your feather, the curve shows up between steps two and three, but is not evident in the direction of step two itself.
Also, any curve you dance will actually lesson the depth of your CBMP position, since it will tend to align your moving foot more squarely with your body - unless of course you dance CBM on 3 to make up the difference, but I don't recall seeing that in the description.
A full swing on the reverse is a function of the body position and momentum you have at that point, not the directino in the room (DC or LOD) resulting from curving or not curving the figure. Of course if by curving you weaken your CBMP, then that will weaken the reverse figure.
This suggests to me that the curve is fairly minor.