This was super helpful! I managed to ticket my mileage award to one of the ExpressRail destinations pretty easily. Didn't get me all the way to where I wanted but very close!
Originally Posted by
threeoh
I think the trains to Stuttgart are through Lufthansa Express Rail, which is different than the QYG Rail&Fly program. With Express Rail, you can check your bags through, sit in a Lufthansa-only section of the train, your connection is protected in case of IRROPS, and you earn miles.
https://www.lufthansa.com/us/en/lufthansa-express-rail
With QYG Rail&Fly you have an open-ended ticket to any DB station in Germany, but no reservations, no baggage service, etc.
On a separate note, I just added a wiki to this thread and put a few links to info on QYG and Lufthansa Express Rail.