I am currently working at the D-KMP navigation. It’s indeed possible to achieve almost similar syntax between Kotlin and Swift.
The extra casting you see on SwiftUI is due to the fact that it’s not possible to export Kotlin Reified functions to iOS (a non-reified function had to be added). But that’s really the only thing.
On the other hand, Swift has the advantage over Kotlin not to require to type the Enum class name.