While the improved camera tracking is pretty visible in the video, most of what I worked on in the past week was under-the-hood: specifically, I've been making the code more general (to make more complex additions easier to implement), and gearing the cameras up for cutting to different angles.
The major change is that simple behavior trees are now involved. Just importing all the right assets and files into my Unity project ended up being more of a hassle than I was expecting, but I got that done. There's now an actual Director too, who is currently just using a behavior tree when deciding which camera to assign an event to—you can see this in the video above, where the Director assigns the first occurring event to the red camera, the next event to the green camera, and so on.
The second major change (which, again, you can't see in the video) is that I redid a lot of the event and camera code, to make everything much more general: now you just tell the spheres what constitutes an event for them (in this case, it's being mobile), and they just tell the Director when they are engaged in an event, and when that event ends (in this case, when they become stationary). The spheres don't have to deal with the cameras at all, and the Director does all the mediating.
Since I think tracking is pretty solid, and I've got the start of behavior trees, next week I will play around with having the cameras cut to different angles. Surprised at how short this post is? Stay tuned for my self-evaluation!