I would have a problem with osty kills....
Just make GV kills, kills landed

Plane kills, killed by who as in WB.
Something stupid that I really enjoyed also were medals. ( no longer being done )
I can show you the day I reached a mark. Can describe the last sortie, it's burned in. It's still there !!! in an arena with 2 people in it now

Medals for milestones are fun. Keeping track of streaks are fun, kill buffer messages are fun.
They add to the whole thing for me. Without them the game is fun, but "alittle" less. But that's me. Kinda cool, look at the date and I remember it all. Came close 3 or 4 times and something would happen around 18 or 19. Kept new furniture being delivered to the house

It would in my view be a good addition.