While working on #1831774: Config import assumes that 'config_prefix' contains one dot only, I realized that breakpoint.module is the only place in core other than storage controllers and the storage controller test that directly translates config object names into config entity IDs.
Also in there are calls like
config_get_storage_names_with_prefix()
drupal_container()->get('config.storage')->listAll()
entity_get_info() x 2
entity_load_multiple() x 2
Those all scream to be contained in a storage controller.