Update: Launcher
There are many ways the user experience is influenced in a game and I've noticed that presentation in Menus is very important and comes in various forms.
After some carefull consideration I've decided to follow what some AAA titles have done by ditching the Fullscreen GUI in favour of a Launch Window.
Of course the game runs in Fullscreen but the launcher allows for the opening of the editors without having a full blown GUI in the way.