Well you had the one fellow we both know who is Japanese and American and is a translator by trade. Hmm....I have about a hundred pages of it in English. I don't think there is much of anything there to help anyone with anything. It's a curiosity at best, self serving at worst. There is enough said to create useless debates for a long time to come.
The one thing of merit is he is yet another one telling people you need to steal it and that there is and was solo training-in his view extraordinary solo training- in order to really "get it." And so what..therein lies much of the debate.
Everybody talks,,train, and then go touch people. Then you'll know. As you well know, most simply cannot deliver much of anything you won't find everywhere else.
I bought a japanese copy a couple years ago and read it, and I agree, it is certainly not a how to book, but, like you said it stresses the need for solo training, and makes it clear that a body built in Sagawa's manner is not a normal body.
The reason I made the above comment was I was wondering more along the lines of included translator notes, to help someone understand what exactly the skill is that is being referred too. Given the amount of discussion here and elsewhere about that skillset and lack of a common language......
Heck, if you haven't actually felt this sort if thing, you might not understand what the "clear power" of the title actualy means.