I see the problem, too: $AUTOLOAD gets the fully-qualified method name, which can be used, but a call with that name will not find inherited methods.

If performance is an issue, you might want to benchmark that solution against:

{
  package File::Collector::Iterator::All;
  sub AUTOLOAD {
    our $AUTOLOAD;
    my $self = shift;
    my $method = ($AUTOLOAD =~ m/::([^:]+)$/);
    $$self->$method(@_) while ($$self->next);
  }
}
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I do not know enough to predict which should be faster.