Haven't read the Carr, but I do like Jack Chambers' bio quite a bit. It does however have a bit of the opposite problem wherein Chambers is unrelentingly critical of the music, not unlike Gunther Schuller in his early jazz and swing books. You'll learn just about everything you need to know about Miles' day to day but come away with the conclusion he only recorded a small handful of truly successful pieces. That said, an interesting perspective that's worth hearing out.
Yes, that is the version I have. It has not been on CD to my knowledge (I think that goes for a lot of the Philips FX-series).
The box set is this:
https://www.discogs.com/release/19128955-Various-All-Japan-Jazz-Festival-71
The other two LPs in the set are trad/swing and by-the-numbers bop revival. The Poll Winners single album is much more like what you’d expect/want for 1971.
Listening to some recent uploads at Vandy on a road trip to Tallahassee, I realized that separated by a few months in 1979, Percy France expressed some related thoughts about ballads, singing thru your horn, and the importance of love.