Thanks for posting the link to Ajahn Amaro's book, Hanzze.
After reading it years ago, I began attending a Dzogchen group (following Chogyal Namkhai Norbu) here and saw many similarities between Theravada and Dzogchen.
In the end, I came back to the bare-bones, do-it-yourself, Theravada rather than the later, more distant in time from the Buddha, Dzogchen teachings.
I have an admiration and respect for Dzogchen.
---The trouble is that you think you have time---
---Worry is the Interest, paid in advance, on a debt you may never owe---
---It's not what happens to you in life that is important ~ it's what you do with it ---