Messy iOS Launch Images (AIR 16.0.0.250)

Hi, since migrating to the "AIR 16.0.0.250" beta I've noticed that my iPhone 5s displays the "Default-568h@2x.png" launch image properly in landscape but then briefly displays a garbled version of "Default@2x.png" in the wrong orientation (which is obviously a bad first impression for users). I have no such issues with a prior version of AIR 16 which I've reverted to.

Can anybody explain what may be happening there and whether it will be addressed in future? I can only hold out so long before I'll need this new version for 64-bit support (which I trust will be available on Windows by Feb).