Re: Removing unloaded functions from auto-mode-alist.

[Richard Stallman]

    So a better expedient would be to have
    (provide 'xxx)

    turn on the necessary action at the end of the current load file in
    case that the feature is provided the first time.

I am not sure if this really solves any part of the question of
how we might try to implement better unloading.  It isn't a design
for an implementation.