rdellconsulting on "wp-query multiple orderby keys"

I'm using pre_get_posts to successfully output a list of CPTs using order as primary key:

add_filter( 'pre_get_posts', 'my_get_posts' );

function my_get_posts( $query ) {

    if ( !is_admin() && $query->is_home() &&  $query->is_main_query() || is_feed() ) {
        $query->set('post_type', array( 'post', 'statsbox', 'imagebox', 'socialbox', 'quotebox', 'linkbox', 'videobox', 'textbox' ) );
        $query->set('orderby', 'meta_value_num');
        $query->set('meta_key', 'order');
        $query->set('order', 'ASC');
    }
}

I'm trying to add another meta_key client_name as primary sort key.

Novice, I've tried:

add_filter( 'pre_get_posts', 'my_get_posts' );

function my_get_posts( $query ) {

    if ( !is_admin() && $query->is_home() &&  $query->is_main_query() || is_feed() ) {
        $query->set('post_type', array( 'post', 'statsbox', 'imagebox', 'socialbox', 'quotebox', 'linkbox', 'videobox', 'textbox' ) );
        $query->set('orderby', 'meta_value meta_value_num');
        $query->set('meta_key', 'client_name order');
        $query->set('order', 'ASC ASC');
    }
}

Any help appreciated!