Overriding & reusing Symfony services by means of .class parameters overrides inside Symfony Dependency Injection Container configuration has been deprecated since Symfony 2.8 (AFAIK). I've identified serveral ezpublish-kernel parameters which are still used instead of the proper overrides:

• ezpublish.view_provider.configured.class
• ezpublish.view.matcher_factory.class
• ezpublish.fieldType.indexable.unindexed.class

It needs to be investigated how extension points can be improved (either by decorating or relying explicitly on a class from SPI namespace).