The great work of @JasonSmith and his team made it possible to push and pop pages without animation. Works perfect on iOS with one exception: if you use the back button to go back, animation is always on. In the documentation you could read, that the static function NavigationPage.SetHasBackButton(Page, bool)should contain a flag for animation or not. But the only flag is for visibility of the back button.
So the question is: how to prevent animation when pressing the back button on iOS?
Btw. on Android all works perfect.