I have. It’s pretty short and to the point. They’re based out of Germany so their requirements for clarity are pretty high by law. They go into quite a lot of detail about what is sent.

In this case they send date, time, language, processing time, number and the type of errors, but not the text itself

However, they do have an optional feature that uses OpenAI to rephrase sentences so that might be training through the back door.

I’ve been using it for years and have been very happy with the service.