Totally revamped ui.alert for the new UI, and used the new implementation to replace the quit dialog in the main menu, making it an alert instead of its own thing (while looking visually the same as it did before). Use the new UIShowSimpleAlert/UIShowOneButtonAlert/UIShowConfirmationAlert/UIShowTwoButtonAlert scripts to tell an alert to show, like how you'd use UIPopViewController or RunConsoleCommand etc.