I jumped into an migration project, and I don't know where the configuration setting came from. And we removed the specification, it has been defined in a project. Inside designer this definition takes precedence of the original definition, e. g. if you define a connection to an engine db on a test server. I think that's the reason someone used it. The application has been developed over more than ten years, and there have been some functions developed in the project which are now available in the API. So I don't mind about the history. It is working fine now since we deleted that database definition.