In plan, it is only possible to associative-label an element on its home story. It should be allowed to label an element on any story it can be shown. Note: ANY, not ALL.
I suspect this is harder to implement than it looks, since all the stories share a window. After all, you can check "Label Elements" on remote stories, it just displays on the home story.
EDIT: It occurs to me that to label remote elements as if they were on the current story would require new globals to describe stories other than the home story. Tricky.