Apple's default calling preference: Convenience init vs Designated init [closed]

lets say i have a CPTemplateApplicationSceneDelegate. Inside it i have a designated init and a convenience init.

Q1. In my POC i see that Apple calls convenience init first. Is there any documentation where this prioritization is defined?

Q2. As you see, my designated init has default values. Does my convenience init provide any value?

class CarPlayTemplateApplicationSceneDelegate: NSObject, CPTemplateApplicationSceneDelegate { /// Designated Init init(playbackController: PlaybackController = .shared()) /// Convenience Init @objc convenience override init() { self.init(playbackController: .shared()) }