I think handles is the clearest and most flexible way to let method calls go through. I use it often when wrapping up objects into an ad hoc API.

use 5.14.0;
use strictures;

package SomeMangagedObject {
    use Moo;
    sub exterminate { 1 }
    sub Exterminate { 10 }
    sub EXTERMINATE { 100 }
    1;
};

package MyWrApper {
    use Moo;
    use Scalar::Util "blessed";
    use Carp;
    has "robot" =>
        is => "ro",
        required => 1,
        handles => [qw/ exterminate Exterminate EXTERMINATE /],
        default => sub { SomeMangagedObject->new },
        isa => sub { "SomeMangagedObject" eq blessed $_[0]
                         or confess "Nope" };
    1;
};

my $wrap = MyWrApper->new;
say $wrap->robot;
say $wrap->exterminate;
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