>>I have no problem sending the whole of an updated module, if necessary

Heh, the only real case for this i can think of is say you offer some kind of script, someone downloads it and makes a bunch of modifications. If you upgrade the script (a function in this case) you would wipe out all those mods if you sent the entire script. Of course this is a rather limited idea i suppose and it makes certain assumptions which by no means are always true. But that was basically my reasoning behind it.