That was a great interview of Erskine you linked to - thanks. Yeah, the movie isn’t about how music instruction happens; it just uses that world to feature an Apprentice vs the Master psychodrama. I enjoyed Erskine’s nit picks about the drum set’s Toms, and needing four beats to count off a song.
As a non-jazz musician, I find the use of that world to be off enough to be a distraction. Frankly, a more subtle jerk could’ve been both more realistic and compelling. After my disappointment in La La Land, I’m not sure how I am feeling about Damien Chazelle.