Thanks ikegami! Playing around with your code helped me learn this cool stuff. I soon realized that I wanted to leave both ArrayRef and Objects alone. Starting from ikegami's code, I added this, cleaned it up (I hope) and am posting it here for reference. Perl rocks! Moose rocks!

{
    package MyArray;
    use namespace::autoclean;

    use Moose;

    use Moose::Util::TypeConstraints;

    subtype 'ValueOrObject'
        => as 'Value|Object';

    subtype 'Inside::MyArray::Ents'
        => as 'ArrayRef[Value]|Object';

    coerce 'Inside::MyArray::Ents'
        => from 'Value'
           => via { return [ $_ ] };

    my $level2_constraint =
        Moose::Util::TypeConstraints::find_type_constraint(
            'Inside::MyArray::Ents');

    subtype 'MyArray::Ents'
        => as 'ArrayRef[Inside::MyArray::Ents]';

    coerce 'MyArray::Ents'
        => from 'ArrayRef[Inside::MyArray::Ents|ValueOrObject]'
            => via { [ map $level2_constraint->coerce($_), @$_ ] };


    has 'myarray' => (
        traits  => ['Array'],
        is      => 'rw',
        isa     => 'MyArray::Ents',
        default => sub { [] },
        handles => {
            push      => 'push',
            pop       => 'pop',
            get       => 'get',
            set       => 'set',
            elements  => 'elements',
            count     => 'count',
        },
        coerce => 1,
    );

    __PACKAGE__->meta->make_immutable;
}


    use Modern::Perl;
    use Math::VectorReal;

    my $a0 = MyArray->new( myarray => [ 0, [ 0, 0, 0 ], [1,2,3] ] ) ;

    use Data::Dumper;

    print Dumper $a0;


    $a0->set(1,'cat');
    print Dumper $a0;
    $a0->push('dog');
    print Dumper $a0;
    $a0->push('1.0');
    print Dumper $a0;
    my $vec1 = vector(1,2,3);
    $a0->push($vec1);
    print Dumper $a0;
    my $vec3 = $a0->get(5);
    my $vec2 = $a0->pop;

    print Dumper $vec2;
    print Dumper $vec3;
    say $vec1-$vec2;


    1;
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