Whilst the reply from the CEO seems sound, their team promptly closed the path the plugin used to make self-hosted full-featured Sync & Publish work. "For Security" - ignoring the handful of other gaping security holes as less important I guess?
Anyway, I decided to fork and make it work with v1.4.5. Enjoy https://github.com/acheong08/obi-sync/issues/19#issuecomment...