Hi,
I'm working hard with configuration system and i encounter some difficulties.
I have already post an issue (https://www.drupal.org/project/drupal/issues/2938658) on a SQL error when updating config on existing language but I have found other cases :
- roles and permissions : Uncaught PHP Exception Drupal\\Core\\Entity\\EntityStorageException: "'user_role' entity with ID 'authenticated' already exists." at /data/web/core/lib/Drupal/Core/Entity/EntityStorageBase.php line 425,
- fields : Drupal error : Unable to install your_module, field.field.node.my_field.field_my_field_date, field.storage.node.field_my_field_date already exist in active configuration.
It appear that the problem s the impossibility some to update configuration for some object :
- languages
- roles and permissions
- fields
The idea is to be able to update only some setting. I could be done with a new parameter on YAML file settings to tell configuration system to load the involved object and replace the settings on the file. Actually it always try to create the object.