So ideally with this, you have small-medium messages and it acts like an in-memory struct but safe and almost as fast.

After you are done processing a message, free it, and it’s done. Usually you would not need to keep one in memory for long, even parts of it (say HTTP request bodies, or logs that get processed and written to a file)

For when you need a subset that is not worth keeping the message around for, copy it, agreed