i have a question about Native UX for IOS development using KMM? Is XCode still necessary for the screens or can it all be done in android studio?

XCode is necessary to run the app

You can do UIKit in Kotlin, technically. Some people do it. You can also hack around and get Compose UI on iOS, though it's experimental and not even official.

Would you say kotlin + uikit is more stable than the latter?

I would definitely recommend using XCode for Screens, especially if you want to use SwiftUI. Like Louis said you can technically do it in Kotlin but it’s not recommended

You say it's not recommended. At least, UIKit is stable and usable on all iOS versions. I'd not rule it out.