This is fascinating. I’ve heard snippets over the years about the importation of kriya yoga and other yogic techniques into Chinese Daoism, but I’ve never looked into any source materials. Thanks for the detailed and poetic exposition. The Persia connection is rich. I wonder if you’ve read Thomas McEvilley’s _The Shape of Ancient Thought_. He looks at exchanges between early Greek philosphy and adepts from Northwest India through the internationalism of the Persian empire. Chinese Daoism figures heavily in his analysis.