That Bug is a Feature
Just finished our second week of going live with K4 v6.3. I have filed a few bug reports and posted a few questions.
Fortunately one perceived but turned out to be a great feature. We just never saw it in the manuals or remember it from the training.
In Adobe InCopy if you have an article open that is attached to a layout, and if you open a 2nd article attached to the same layout, the 2nd article does not open a new window. You edit the 2nd article in the same window as in the first article. If you are in Story or Galley view you will see the 2nd article’s text objects at the bottom of the window. In Layout view you can simply edit the article.
You can see the change by opening an article, switch to Layout view, set Dim Other Items and then open a second article attached to the same layout. You will see the text associated with the 2nd article suddenly become undimmed.