Back to the drawing board
So we went back to the drawing board and asked ourselves; what are the minimum changes we can make to the existing familiar UI to make those features more clearly visible? We tweaked the icons, added text labels, and split the voice feature into its two important but separate use cases: dictation and conversation.
This worked! Usage of all features increased across the board, with the handwriting being used as much as 25% more than it was before! We even started seeing tweets from people who thought these were new features, even though they had existed for years.