[johnecheck]

"Proper behavior"... You've defined this term as the precise behavior of the technology that Flutter aims to supplant.

Indeed, Flutter will never do everything "properly". But that's not its selling point. It doesn't need to, as long as the number of users reached from a multi-platform release outweighs the users lost because they were offended by a missing native feature. (Assuming you're not some massive company developing a parallel app for each platform)