1. Open something which has multiple text fields, such as the Mail compose new message screen.
2. After writing something and then moving around the screen with QuickNav on, press either a Cursor Routing button on a braille display or the up and down arrows to select the next desired text field.
3. When you do, regardless of Verbocity settings, VoiceOver only plays the sound to indicate that QuickNav has been turned off. There is never speech or braille feedback given in this set of circumstances.