There's more than one way to be friendly. :)

I don't balk at extra arguments either - this can be very useful, as wrappers can just call the function with whatever @_ they were called with.

The downside of allowing extra args is of course the classic misspelled_lable => 'uh-oh' problem. If such an error isn't caught right away, that can result in some very unfriendly bugs, depending. Do you perform any extra verification to defend against that class of problem?

Unchecked labels really get ugly if there are default values...