> User calling thread.
> `def start` is supposed to be called at system startup (can be done later also) to register the supported types, that then can be used with `def shardRegion`. Since this should not be too many and not on any hot path, I found it easiest to do it the blocking way (even though it hurts a bit in my soul).

Remoting also has it in two places, for the very same reason. I just wanted to know on whose thread this Await ends up. Thanks for the clarification.