I am extremely dubious about the usefulness of this particular endeavour, now having the book, and having read quite a chunk of it.
First and foremost, the author, Elna Matamoros was a pupil of Leif Oernberg (uncle to Peter Martins of NYCB), and his wife Elna. The reason that Leif Oernberg found himself in Madrid after WWII goes well beyond the term "controversial".
In French terms, he and his wife were deemed to be "collaborators" with the German invaders, and, if I recall aright, were told to leave the Royal Theatre at Copenhagen after the War. This is well-documented.
So, believe as one does in being extremely generous with one's "enemies" so to speak, somewhere, there must be limits. I would not suggest in any shape or form that Miss Matamoros (despite her name!!!) might entertain even the remotest affinity with the political views of her professors, but neither would I, personally, care to promote any endeavour related to that particular pair.
Secondly, the illustrations in the book, posed by Tamara Rojo and a Spanish gentleman, Sergio Garcia, who would appear to be of rather middling ability, are unfortunate, and fail to reflect the essential features of the Bournonville technique - let alone its "aisance". Tamara Rojo, although she is pretty as a picture, and on stage, a good actress, practices wild hyper-extensions nor can she, in any sense of the term be described as a Bournonville dancer. Why she should care to pose as one, is a mystery.
Thirdly, in 2005 the Royal Theatre published a three-volume work on Bournonville technique, in English (DVD, the Schools in detail, and the scores). Whatever reserve one might have about this or that detail, and despite one's doubts about the presence of Fernando Mora on the film, this was a MONUMENTAL endeavour. Any professional can now take the Schools volume, sit there with the DVD, and grasp - at least in outline - the choreographic and technical ideas that lie behind the enchaînements. To bring out a book in Spanish a mere three years later, adds nothing.
The sole original feature of the book is the chapter on the Escuela Bolera and Bournonville. This is so important, that it is worth a BOOK, not a chapter.