Did this get anywhere?
Or is there another way of getting what I want to achieve - to have a corkboard in one window, and a scrivening of the items shown in that corkboard in the other?
This feature should pop up in the future, we did decided to include after all.
For now though, and this is what I do as well, click on the thing in the Binder that you wish to double-load, which will load it into one of the editors, and then hit the keyboard shortcut that loads it in the other editor (Documents/Open/in Other Editor).