I've since written a fairly complete blog post only on overload management of asynchronous systems at https://ferd.ca/handling-overload.html -- it hasn't made it in the book, though.
In particular the 'fuse' type stuff is really important when you have a real world system where "let it crash!" is not really ok, because you have, say, a user interface, or a web server that should not be part of everything just crashing. In particular, something I've seen: if your Erlang application talks to a database, and the database goes down for some reason, it may be desirable to have the whole application not go down with it!
