Am I missing something?
Inside Perl 5, a reference only has one slot to associate it with a class. You can replace that association by blessing the reference into a different class, but there's only ever one class associated with a reference.
I don't know what object system you're thinking of, but this is how Perl 5 has worked since the beginning. Test it and see:
package Grandkid;
use parent 'Kid';
sub new { bless {}, shift }
package Kid;
use parent 'Parent';
package Parent;
sub inherited_method { 'Yep, inherited!' }
package main;
use Test::More 'no_plan';
my $gkid = Grandkid->new();
isa_ok( $gkid, 'Grandkid' );
isa_ok( $gkid, 'Kid' );
isa_ok( $gkid, 'Parent' );
is( $gkid->inherited_method(), 'Yep, inherited!', 'method inherited fr
+om grandparent' );
done_testing();