This is the first beta release of External Entities.
The is still a lot of work to be done, much work has been done and the module is pretty stable. The module is in use in live websites, some of which with a lot of external content.
#3272698 by attiks: Entity reference fields are populated when empty
#3262870 by pgrond, attiks: drupal breaks because missing config.translation_overview on external entity
* Entity type based instead of bundle based. As of 2.x, each external entity type is its own entity type.
* Storage client improvements. In 1.x the provided storage settings are independent of the storage client that is chosen. Now each storage client plugin can provide its own configuration.
* Storage clients can now provide a specific implementation for count queries.
* Storage clients now have the possibility to load multiple items at once.
* Various enhancements to mapping field data