If you do this, you may want to provide a new can() method for people to use:

# can - Help UNIVERSAL::can() cope with our AUTOLOADed methods
sub can
{
    my ($self, $method) = @_;
    my $subref = $self->SUPER::can($method);
    return $subref if $subref; # can found it; it's a real method

    # Method doesn't currently exist; should it, though?
    return unless exists $self->{$method};

    # Return an anon sub that will work when it's eventually called
    sub {
        my $self = $_[0];

        # The method is being called.  The real method may have been
        # created in the meantime; if so, don't call AUTOLOAD again
        my $subref = $self->SUPER::can($method);
        goto &$subref if $subref;

        $AUTOLOAD=$method; 
        goto &AUTOLOAD 
    };
}
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(This one assumes that people will often call can() without intending to use the method ref it returns, and so it defers calling AUTOLOAD until someone goes to use it. Because of this, it needs a second check to see if someone else has already AUTOLOADed the desired method in the meantime.)