I assume you would be communicating pointers with actor mailboxes, so the only copy is a pointer. I believe Erlang copies data itself into other actor's heaps, that simplifies garbage collection since GC can be done per process and there is only one owning reference to a processes' data.

You might find Pony's ORCA interesting which is how they implement garbage collection between actors.

https://www.imperial.ac.uk/media/imperial-college/faculty-of...