Hi Heiko, it depends what you mean with 'cluster-aware' :)
The plugin is basically just an actor, that manages a Map instance, and is launched by akka-persistence, and handles its messages.
The plugin was created with one simple use case; I wanted to learn akka-cluster, and wanted to learn it by means of unit testing, and the plugins at the moment (some time ago) didn't have snapshot in-memory support, and as you know, akka-cluster uses snapshotting, and cleaning up the directory with snapshots what the solution at the time.
Alas, there is no implementation to synchronise multiple instances of the map using a consensus protocol like eg. raft. I'm open for a PR for such a feature !!