@saschaeggi Will this code be added to the 4.x branch?
@koosvdkolk In js/navigation/sidebar.js of the 8.x-3.x branch of the module, it's set up to work with (e.ctrlKey || e.shiftKey || e.altKey || e.metaKey), so I suppose you can use any of those 👍
Pushed up what I had to a new branch here: feature/1.x-accordion-component
Working on this at Florida Drupal Camp!