ios – SwiftUI (2025): best practice for a keyboard-aware chat composer — pure SwiftUI or wrap UIKit inputAccessoryView?

Goal: A ChatGPT-style composer fixed at the bottom, always above the keyboard, supports interactive dismissal, growing text, and iPad undocked/split keyboards.

Tried:

1. Pure SwiftUI: .safeAreaInset(.bottom) + .scrollDismissesKeyboard(.interactively) → during interactive drag the panel sometimes lags/briefly shows a gap; growing text can cause small jumps.

2. .toolbar(.keyboard) → not persistent when there’s no focus.

3. UIKit wrapper with inputAccessoryView via UIViewControllerRepresentable → smooth, but only visible while a field is first responder.

Minimal repro (SwiftUI):

import SwiftUI

struct ChatView: View {
    @State private var text = ""
    var body: some View {
        List(0..<40, id: \.self) { i in Text("Message \(i)") }
            .safeAreaInset(edge: .bottom) {
                HStack {
                    TextField("Message", text: $text, axis: .vertical)
                        .lineLimit(1...6)
                        .textFieldStyle(.roundedBorder)
                    Button("Send") {}
                }
                .padding()
                .background(.ultraThinMaterial)
            }
            .scrollDismissesKeyboard(.interactively)
    }
}

Observed: On iPhone (iOS 17/18) there’s a brief 2–8 px gap/lag vs. keyboard during interactive dismissal; on iPad with undocked keyboard the panel may not “follow” the keyboard.

Question: In 2025, is there a pure SwiftUI pattern that reliably matches inputAccessoryView behavior (including interactive drag and undocked keyboards), or is the recommended approach still to embed a UIKit controller and use inputAccessoryView? Are there any Apple docs or sample code available for this?

Environment: Xcode 15/16, Swift 5.9/5.10, iOS 17