It would be more minimal to hide the iOS date and battery status.
We believe in most cases people would want to keep this info visible.
But it would be a good optional feature, for better focus.
We’re very strict when it comes to optional features, especially if they would require some kind of setting or preference. In this case while I could see it would reduce distraction in focus mode, I don’t think it warrants the addition of extra setting I’m afraid.
Maybe it would be good as a full screen mode in the note settings.