a possible solution to the notation editor blues?

Lately I have been working with a friend and he is using a different DAW.
The way the notation editor works there is simple and ingenious: The piano roll page has a "score" button that opens a lane that runs parallel and that contains the score editor. That way you can write the note on a staff but tweak length, velocity and other stuff on the piano roll, with immediate visual feedback.
Is it very hard to implement? I think that would maybe solve some of the issues with the score editor?