Don't you think it makes better sense if you consider all three steps as a progression?( CP-CBM- CMBP)

"Don't you think it makes better sense if you consider all three steps as a progression?( CP-CBM- CMBP)"

Yes, but the actual progression is more like

1) use CBM
2) now you have a side lead
3) now you are in CBMP

The action occurs during step 1, the positions on step 2 & 3 are really the same, but termed differently (side lead vs. CBMP) because they are defined in reference to which foot is the moving one.

True- considering the total actions.

Could not the third step be to CP? Wouldn't be a Feather of course.

Just wondering what nuts and bolts was considered when the phase, ‘ prepare to go outside lady'was used.

I would interpret the term CP to mean Closed Position in this instance; Counter-prom would usually be CPP.

Now for some history:

Alex Moore editions 1 to 5, 1936 - 1947, describing the feather danced straight down LOD, step 2 "LF forward, on same LOD, but body turned slightly towards wall". No mention of preparing... or side lead.

Henry Jacques, Modern Ballroom Dancing, 1st edition, 1944, step 2 "Forward Left foot, a medium length step, preparing to step outside partner on right side."

Alex Moore, 6th edition, 1951, step 2 "LF forward, preparing to step outside partner, L shoulder leading."

Of course the shoulder lead has of more recent years become a side lead but the basic idea is the same and the two parts of the description complement each other. The shoulder/side lead prepares for the next step to be taken in CBMP which is a vital part of the OP position.

The term " shldr " was abandoned as a descriptive element some time back ( I personally championed that cause )

it invariably conveyed the wrong message .

And remember-- the " book " is primarily designed as a foundational tool for class and exam work .
Objective ?-- standardisation .

"It might have been better if the book had said the lady allows the man to be on the outside on step three. The man takes the straight line. The lady makes space so that he can. Also that CBMP on the third step is more severe than most of us try to be."

It is true that the man shouldn't detour outside the lady, in fact, he should be stepping slightly to the right of continuing on a straight line of progression. This is because the third step is merely forward in CBMP, not forward & across in CBMP. This means that the third step will extend the line of the foot from the second step, but must not actually cross it.

The tricky implication of this is that while the feather has nothing that meets the definition of turn, the track of the steps actually does curve slightly to the right in the official version - because to take it straight, you would have to step ACROSS in CBMP, and you are not directed to do so.

The practical implication isn't far from what quickstep said - the man should not detour around the lady, in fact he should move slightly at her on the third step - her right hip has to stay in front of his, no slipping off to each side.

Paul and dot. To get a better idea of a Reverse Weave in the Waltz. Take a look at the chart of the ladies steps. You will see that between 2 and 3 after the turn it is clearly a side step. Then between 5 and 6 is another side step. Its been that way since before the book was first written over 70 years ago. It takes some people time to catch up it would seem watching some of the instructions I have witnessed by people who haven't got a clue.
It might have been better if the technique book had said preparing to be outside the lady at the end of step 2 . Alex Moore was a very precise person. When he writes just once. The insides of the feet at both the toes and heels brushing past each other every time the feet pass. He has told you once you will be expected to do this from then on without any more reminders. So apply that to your Weave or Feather Step or any other step you may do in any dance.I think they call it tracking when the feet stay inside the line of the body.
Excuse my ignorance but what is meant by CP. Is this a new term that has crept in.

cp-- counter prom.

Serendipidy I agree the dance track has been established at the end of 2. But remember Step 2 has a beginning and an end. I understand all your points and agree with everything including, Alex Moore was a very precise person- Carry that idea to your original question, PREPARE is very precise- In the framework of the entire description the word ‘PREPARE is very powerful. It suggests something is going to occur maybe not totally under the Man's control. PREPARE does not propose he do anything, just that he gets ready to do something. The words “to step” tell the man what to do, the word OUTSIDE tell him where to step to reassure he not does step back inside. The final step outside makes the narrative complete in my mind.

Here's another to examine. In the Foxtrot is the second step of a Reverse Turn a step to the side or is it a step that travels which would be more to the rear. Before anybody makes up their mind go to Marcus Hilton Basic Foxtrot on youtube.