Good post - I entirely agree - design for cognitive mapping is key:
"Cognitive maps are the result of a type of mental processing in which a user acquires, codes, stores, recalls, and decodes information about things of interest in their environment. When used in the navigation of transmedia narratives, cognitive maps allow the “mind’s eye” to visualize the relative location of and links between different elements of the narrative, substantially reducing the user’s cognitive load while enhancing the recall of information.
Facilitating the creation of the user’s cognitive map of the transmedia narrative (and ideally the entire storyworld) makes it significantly easier for the user to navigate between story elements and maintain the continuity of the overall narrative. As a result, the cognitive load on the user is substantially reduced when having to make decisions during the user interaction cycle....."