Diff does not detect anomalous configuration

In order to use Diff, you need to setup server computer, install the MariaDB Server version to be assessed on it, and make it replicate from the primary used in some MaxScale service setup. And then you need to create a MaxScale configuration server for it. However, that server must not be added to the original service. That is an easy mistake to do so Diff should detect that and refuse to start if that is the case.