Load Relationships Always, but Dynamically

You can not only specify what relationships to ALWAYS load with the model, but you can do it dynamically, in the constructor method:

class ProductTag extends Model
{
    protected $with = ['product'];
 
    public function __construct() {
        parent::__construct();
        $this->with = ['product'];
 
        if (auth()->check()) {
            $this->with[] = 'user';
        }
    }
}