I encountered this issue while actively developing a custom distribution. Even in a development environment, where we frequently reorganize things and delete irrelevant or incorrect configurations from features, we're somewhat blocked and have to write hook updates to manually delete configurations. It would be really helpful if config_sync could facilitate configuration deletion, similar to how it handles creation and updates—at least in a destructive manner without dependency checks, leaving that responsibility to developers for testing.
There is a case when Content Entity Type constraints do add error messages during form validation. Those are keyed with empty string in form_state_errors array in comparison to field level errors, which are keyed by parents path to field. There is a case when $error_key can be calculated as an empty string, thus doing a collision and grabbing top level form error and assigning as an error for each $untriggered_dependents fields. Later on this throws all the remove\add back logic under the bus and dismisses the top level form errors as result.
My addition to patch #149 add a simple check for non emptiness of $error_key, as top level form errors should not be matched against any field.
Patch re-roll for Drupal core 10.2
As of patch https://www.drupal.org/project/embed/issues/3310328 📌 When CKEditor5 is installed, only allow SVGs for button icons Fixed in Embed module all buttons require and SVG icon to be displayed.
I have amended the patch to use CKEditor5 icon.