This is not very much aligned with the current plugin architecture. The akka-persistence plugin architecture is conceived to allow append only inserts with asynchronous propagation to the query side. You want strict consistency around write and read side.
It’s also so that you can’t have access to plugin infrastructure components from inside the actor. The PersistentActor must stay agnostic of the underlying plugin implementation. That’s actually what allows us to have different plugin implementation for completely different database technologies.
However, you can try to customize the JDBC plugin for your needs.
The JDBC has a DAO layer sitting between the plugin API and Slick. You can implement your own DAO variant that takes the events, processes it like you would do when consuming the events on the query side and let them be save all together with your view model on the same transaction.
Note that you won’t be able to run JPA code in there. You will need to use Scala, Slick and probably some raw SQL, so I’m not so sure if that will fit your needs.