Here's a screen shot from of me over Texas when my GPS dongle quit in flight.
While it should be obvious that I've lost GPS signal (own ship moved to center, the red filled warning box and the dashes in some GPS derived fields), what counters this is that I still have the blue arrow (Course line?) showing on own ship. That's what I was focused on, and I guess I saw what I wanted to see.
I submit that, technically, whenever GPS signal has been deemed lost by the box that the blue arrow, compass rose, intended track line, or any other graphic that is GPS derived should disappear when GPS is lost. (Or flash with the last known data.)
Unfortunately, for set up purposes, when we're sitting at home, perhaps without GPS acquired, we need to see those elements as we play with how we want iFly to look. So these elements should only disappear after GPS has been acquired and then lost. (Wouldn't need this logic if the elements flashed instead of disappeared.)