Thank you, Quinn, that's very helpful. Thanks also for the list of gotchas. The keychain change is fine for me, and the current extensions and watch apps already use the Team ID. I'll update this thread once the migration goes through, so anyone who finds it later knows how long it took. As it has been more than 2 weeks since the last communication from them, I am not holding my breath though.

Adding the LSMinimumSystemVersion key to Info.plist did indeed work after sending an update including it, even though App Store Connect still does not have a macOS 26 option.

Fixed in iOS 26 beta 7.

I have no idea why Apple still does not let us block numbers using simple prefixes in 2025. If I want to block a full number range, say +1-212-#######, I should simply be able to enter +1212 (and perhaps enable a flag) and be done with it.

Still present in iOS 26 beta 6. I suspect the reporting feature will be removed from iOS in the near future.

On iOS 17 and earlier, a CallKit extension would be able to block a number regardless of it being added to contacts or not. With iOS 18 and later, this behavior changed and contacts have the top priority.

You are receiving the notification in an arbitrary background thread. Make didReceive nonisolated and do whatever you do inside it, in a MainActor isolated task. Do not change willPresent to nonisolated. It needs to be called on MainActor since it is a function about the user interface. If you are posting the notification yourself, I recommend posting it on MainActor to get rid of most concurrency related issues. Be aware that the system and frameworks will continue posting from an arbitrary thread.

This still happens with Xcode 26 beta 5. It also happens in all iOS versions below iOS 26, not only on iOS 18.

If this is a UITableViewCell, I have moved all code regarding a variable in awakeFromNib to the corresponding variable's didSet. If the variable is an @IBOutlet, didSet runs only once and works exactly like awakeFromNib.