Environment: iOS 18.7.8, CallKit + PushKit VoIP. On VoIP push we call reportNewIncomingCall and show the system CallKit UI. Goal: When the user declines from the CallKit UI, send a single HTTPS POST to our backend in realtime, across all app states. Problem: Foreground and backgrounded states work. When the app is terminated (system-evicted or user-force-quit), the push launches the app, CallKit shows, and we receive CXEndCallAction — but the network request doesn't reliably leave the device. The process is suspended/terminated moments after the action returns. Tried: URLSession.shared dataTask inside CXEndCallAction — frozen with the app; resumes only on next foreground launch. beginBackgroundTask(withName:) around the request — insufficient when terminated. Background URLSession (.background, isDiscretionary = false, sessionSendsLaunchEvents = true, uploadTask(fromFile:), body staged in Caches, held briefly with a task assertion). Reliable when backgrounded; still unreliable/delayed when terminated, especially after force-quit. Questions: Is reliable, near-realtime client network delivery from a terminated, PushKit-launched app possible, or is this an inherent platform constraint? If it's a constraint, is the recommended pattern to treat the decline as best-effort and make the server authoritative (e.g., ring timeout)? Any official references? Does force-quit vs. system termination change background-execution / background-URLSession guarantees, and is there a supported approach for force-quit specifically? Any API we missed (e.g., a sanctioned way to extend runtime during CXEndCallAction, or background-URLSession scheduling guarantees for VoIP) that makes this realtime-reliable?

I am building a video conferencing app using LiveKit in Flutter and want to implement Picture-in-Picture (PiP) mode on iOS. My goal is to display a view showing the speaker's initials or avatar during PiP mode. I successfully implemented this functionality on Android but am struggling to achieve it on iOS. I am using a MethodChannel to communicate with the native iOS code. Here's the Flutter-side code: import 'package:flutter/foundation.dart'; import 'package:flutter/services.dart'; class PipController { static const _channel = MethodChannel('pip_channel'); static Future<void> startPiP() async { try { await _channel.invokeMethod('enterPiP'); } catch (e) { if (kDebugMode) { print("Error starting PiP: $e"); } } } static Future<void> stopPiP() async { try { await _channel.invokeMethod('exitPiP'); } catch (e) { if (kDebugMode) { print("Error stopping PiP: $e"); } } } } On the iOS side, I am using AVPictureInPictureController. Since it requires an AVPlayerLayer, I had to include a dummy video URL to initialize the AVPlayer. However, this results in the dummy video’s audio playing in the background, but no view is displayed in PiP mode. Here’s my iOS code: import Flutter import UIKit import AVKit @main @objc class AppDelegate: FlutterAppDelegate { var pipController: AVPictureInPictureController? var playerLayer: AVPlayerLayer? override func application( _ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]? ) -> Bool { let controller: FlutterViewController = window?.rootViewController as! FlutterViewController let pipChannel = FlutterMethodChannel(name: "pip_channel", binaryMessenger: controller.binaryMessenger) pipChannel.setMethodCallHandler { [weak self] (call: FlutterMethodCall, result: @escaping FlutterResult) in if call.method == "enterPiP" { self?.startPictureInPicture(result: result) } else if call.method == "exitPiP" { self?.stopPictureInPicture(result: result) } else { result(FlutterMethodNotImplemented) } } GeneratedPluginRegistrant.register(with: self) return super.application(application, didFinishLaunchingWithOptions: launchOptions) } private func startPictureInPicture(result: @escaping FlutterResult) { guard AVPictureInPictureController.isPictureInPictureSupported() else { result(FlutterError(code: "UNSUPPORTED", message: "PiP is not supported on this device.", details: nil)) return } // Set up the AVPlayer let player = AVPlayer(url: URL(string: "http://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4")!) let playerLayer = AVPlayerLayer(player: player) self.playerLayer = playerLayer // Create a dummy view let dummyView = UIView(frame: CGRect(x: 0, y: 0, width: 1, height: 1)) dummyView.isHidden = true window?.rootViewController?.view.addSubview(dummyView) dummyView.layer.addSublayer(playerLayer) playerLayer.frame = dummyView.bounds // Initialize PiP Controller pipController = AVPictureInPictureController(playerLayer: playerLayer) pipController?.delegate = self // Start playback and PiP player.play() pipController?.startPictureInPicture() print("Picture-in-Picture started") result(nil) } private func stopPictureInPicture(result: @escaping FlutterResult) { guard let pipController = pipController, pipController.isPictureInPictureActive else { result(FlutterError(code: "NOT_ACTIVE", message: "PiP is not currently active.", details: nil)) return } pipController.stopPictureInPicture() playerLayer = nil self.pipController = nil result(nil) } } extension AppDelegate: AVPictureInPictureControllerDelegate { func pictureInPictureControllerDidStartPictureInPicture(_ pictureInPictureController: AVPictureInPictureController) { print("PiP started") } func pictureInPictureControllerDidStopPictureInPicture(_ pictureInPictureController: AVPictureInPictureController) { print("PiP stopped") } } Questions: How can I implement PiP mode on iOS without using a video URL (or AVPlayerLayer)? Is there a way to display a custom UIView (like a speaker’s initials or an avatar) in PiP mode instead of requiring a video? Why does PiP not display any view, even though the dummy video URL is playing in the background? I am new to iOS development and would greatly appreciate any guidance or alternative approaches to achieve this functionality. Thank you!