This was bothering me as well. Living in Germany I was looking for such places in MSFS.
There is a decent freeware scenery of the Wasserkuppe on flightsim.to for download.
The fun fact is the "Hornberg" a small glider airfield in south Germany is included by Aosobo by default and looks quite nice. I did glider training there in the 70ties. Close by also "Amalienhof" glider airfield is included default as well.
Regards from an old Flightsimmer