I have not actually used Ink myself. But from looking through the introductory documentation, the world model seems fairly simple and more like the branching na

I have not actually used Ink myself. But from looking through the introductory documentation, the world model seems fairly simple and more like the branching narrative type you mention -- and nowhere near as sophisticated as Inform 7 which can essentially do almost anything and parse any phrase. Which makes sense given the very different needs of a CYOA system like Ink (with restricted choices). However, Ink does support some state variables (like whether you visited a location) so it can be somewhat more complex than just a branching narrative. Ink may also have other features that were not obvious to me at first glance though. I agree with you that a simpler approach can help someone focus on the story -- which was part of a conscious choice to limit StoryHarp's possibilities via only support simple rules. Although another aspect of that limitation was to make the GUI easier to write and to use -- especially by not having to support editing arbitrary logical statements and not supporting state values that could be other than booleans. While the StoryHarp map is most obviously used to map out locations (or "contexts"), the framework is flexible enough so that these contexts could be any sort of general states like, say, moods (angry, sad, happy, etc.) or general situations (desiring a pet, talking with pet shop owner, inspecting parrot, talking with pet shop owner again, etc.).