Due to a security issue in the jsonpath libraries from Goessner and peekmo/jsonpath, support for these libraries have been removed in this release. Now only the flow/jsonpath library is supported. If you don't use the JSONPath parser in your Feeds importers, then there's nothing you need to do.
updated deprecated Drupal 8 code, to bring the module closer to Drupal 9 readiness. The module now requires Drupal 8.5.0 or higher. A protected object inside the AcsfDuplicationScrubEntityHandler class has changed slightly so anyone extending this class should doublecheck their code.
added compatibility with Drush 10. Customers should test thoroughly before pushing a codebase to production that includes Drush 10.
various topics are documented in the readme.md file.