Thank you for your book reviews! I'm about 8k, so I think that most of them are probably way above my head. In some cases, you wrote your estimate of the rank for which they are most useful. Would it be possible to write that for each of the books? (BTW, see also Icons for difficulty scale.)
I've tried to do that to some degree, but not consistently. When reading, for example "Keshi and Uchikomi" as a 2 dan I have no idea how useful it would be for an SDK. Where I felt that there's a reasonable lower limit, I've said so in the reviews. It'll still vary from person to person.
You have a point that it may be not so easy for you to know how useful it is for a beginner, and I respect your zurückhaltung in this regard. I'd like to encourage you a bit, though: You probably have a better idea of this than you think; you've been a beginner once, and you probably meet beginners all the time, so you see what problems they have. Anyway, thank you again for writing your reviews here.