I am just trying out the Free Trial of SD.

Here in southern Germany I am unable to see the standard Airspace C starting at FL100.
I can see C starting at FL130 in the alpine area, but not the standard C in the flatlands.

Same goes with airspace E. Visible when the lower limit is off-standard (like 1000ft)
but not when standard (2500 ft).

What am I doing wrong? Thanks a lot!

(and yes, I have well planned a route high enough - currently FL150)

No, my reasoning is different. I argue not to show it in "what's here" if, and only if, the user opted not to show it. You, as I understand, don't show it because you have made an executive decision as provider of the software.

In my scheme, if the user decides to show airspaces above FL100, it would show up even if it still isn't depicted on the map. In your logic, as I understand it, it still wouldn't show up. So if the user asked SD to show all airspaces up to and including FL100, you don't comply and rather present incomplete information. This can result in very undesirable consequences when in flight.

-- Chris.