I could rewrite it to use tags (that's what I ment by letting user specify owner name), but there no point. I just checked how `findTaggedServiceIds` is implemented, and I found out, that it loops through all definitions. See for yourselves:
https://github.com/symfony/symfony/blob/master/src/Symfony/Component/DependencyInjection/ContainerBuilder.php#L1037

Since my implementation loops only through aliases, it's actually more efficient.