Yeah, this is my wish also. It takes surprise away if I have to use Mission Editor for changing plane to something in WW2.
The feeling I got when I cold start the Bf 109 and check the kneeboard where the enemy planes are sighted, rotate the compass on correct angle and maybe use clock to calculate time for a trip... No GPS or flyight computers, I have to watch and use landmarks for navigation, "Hey, I know that lake!"
I wonder if I could do this myself. If I make 2 identical missions where is only 1 enemy plane but in different positions. Then I find the differences on these files (=position of the enemy) and change it "randomly"?