Here's a small idea:
Make it possible to change the name of an aircraft type when creating a mission/campaign, ideally a different name for each side. This is so the mission creator has more power to use historically-correct designations, or use 'hack' substitute aircraft.
For instance, if the British called the Bf109 the 'Me-109' during the Battle of Britain, it would be more immersive if, when you shoot one down flying for the RAF, the generated mission debrief displays 'Me-109' instead of 'Bf109E3'. This would also affect the icons if they're turned on. If you're flying for the Luftwaffe you'd see the Luftwaffe designation 'Bf109E3', if that's how the Luftwaffe knew that aircraft type. The RAF knew it simply as a 'Me-109' or 'Me-109E' (only after the -F is introduced perhaps?) so that's what RAF players would see in reference to that same aircraft type.
Or if you're using an aircraft as a hack you could 'officially' rename it to the type you want to simulate. Hacks are a good way to simulate less-important aircraft which don't get modelled, and allowing them to be properly renamed would be quite helpful!