Just wondered is it possible to get SD to display the class of airspace that you are currently flying in? SD gives plenty of warnings of controlled airspace ahead, but if you miss these it's not immediately apparent when you're in controlled airspace, especially if you inadvertently climb into airspace above (not that I'd do such a thing of course!).
Perhaps the plane icon could change colour or something, so it would be obvious that something was wrong if you were not in the class of airspace that you expected to be.

K