if the class "new" is not useful, change it to "composer" :) I really prefer that we use classes instead of dataset for styling. And if you add it here, you'll have 2 different states in the DOM, that we need to keep in sync... I don't think this is a good idea in the long term.

Now I understand that using a dataset can be less errorprone than using a class (it's easier to change once, instead of remembering to remove/add classes in the body).

Ok, let's keep this for now, but maybe we'll need to revisit after the navigation patch.