When calling the SEN number you might be rerouted to any LH callcenter (personally I'd assume that those are even the same callcenters used for the FTL number, but that's just me).

As a few of us here have realized that there are minor discrepancies in competence between different stations. Kassel seems to be the last real comptence resort, usually figuring things out to which other centers just stated "Not possible. Pls. don't call again in this matter for you not wasting my precious time. No, pls. don't speak now. I'll just hang up."