It would be really cool if we could draw/write on to the Notes in Whiteboards, and whatever we draw/write actually stays on that note.
This would be useful for writing as if in real life on a Post-It note (as writing on a tablet/Wacom pen (or similar) can often feel more "real" than typing everything, similar to an actual pen). This can give you a better sense of connection to what you are writing down.
Also, this would enable you to add colour marks to to the Notes. So you can see how one note might relate to another, or several others, by drawing a little coloured dot/multiple coloured dots on them.