As MDCPresentationController is responsible for the presentation of your custom view controllers, it does not implement any accessibility functionality itself.
-accessibilityPerformEscape BehaviorIf you intend your presented view controller to dismiss when a user in VoiceOver mode has performed the escape gesture the view controller should implement the accessibilityPerformEscape method.
- (BOOL)accessibilityPerformEscape {
[self.presentingViewController dismissViewControllerAnimated:YES completion:NULL];
return YES;
}