It Is useful to have a range of chords for each semitone,but rather wasteful of space.
As a practical tool to use for chord changes in a song not very useful. It relies on being able to remember the main chords and then use the book for incidental chords like B7sus4.
A single inversion is given for each chord and the entire series relies on instruments being tuned GDAE or a fifth below that forthe banjo and mandola.
All in all I did not feel it was a very comprehensive book and the likelihood of needing D7-9 seems remote to me.
Having said that it is a useful reference even if not much used.