When you create new tracks in an open project, they are simply displayed below the existing tracks in the Audio Mixdown window:
Not in the order they are listed in the project. You have to close the project first and then open it again to make the order match the project again:
I readily admit that this is a very, very small bug. But it annoys me personally. So it would be great if the order would update immediately.
And while I’m on the subject of wishing: I would like it if you could also sort the channels in alphabetical order.
That’s about it. (I still have a few wishes, don’t worry. 
)