I don't think that's a very apt metaphor.
Beginning students of musical instruments are introduced to scales when they first start. I have heard that high level payers of musical instruments typically spend a great deal of their practice time working through scales.
I think the point of what we are talking about Ueshiba talking about is that practice of technique is supposed to yield more than good technique. Not that the techniques are a side matter or something you transition from.
Arguing over metaphors just goes down a black hole. My point is the same, Morihei Ueshiba stated repeatedly that technique was not the heart of the matter. Folks may disagree with that, and that's fine, everyone's entitled to their own opinion.