I like that, and is one I'm considering, because the configurer will type the same kind of structure that the callback gets. But I'm expecting most things to have no arguments, so I don't like needing the arg.
Comment on Re: (tye)Re: Ways of Passing Configuration Parameters
Well, another advantage I've found with this is that you
can make changes more easily in many cases because:
subr( { ..., debug=>0, ... } )
is often a smaller change than having to drop or insert
an argument. (: