In last year @Gil Goldzweig I was thinking in use the Flutter Engine with Kotlin Native and write a Flutter in Kotlin because I really love the kotlin language, but I never found a away to even try that, and Flutter Engine is written in C++ and it makes things harder for me.
Backing to compose, the guys from compose don't need to think about it and don't need to do nothing about it too, but will be great if they build the compose to this be possible in the future with some project from the Kotlin community, porting to iOS(I don't know if the guys is thinking about it, because they have so much work to do in compose). (sorry my bad english :S)