EPPO: But why in the world someone who takes (unlawfully, let's suppose) control of the a/c would want to follow a route neatly through all those wpts? If he wanted to take it somewhere, it would be more logical to fly direct.
If it stays on UARs on the associated track, then radar operators would be more likely to overlook the track as an expected everyday blip. It's entirely possible that people would just mentally filter it out.
As soon as you go off-route and start flying direct, then that would be an unusual occurrence that you'd pay more attention to.