This will sound boring but I'm curious about reading books and comics on the Vision Pro. It'd be interesting to experiment with eye tracking and hand gestures for turning pages, setting highlights, and searching through a book with a feature like Kindle's x-ray.
Comics might be tough because the page format conflicts with comfort guidelines (windows should be constrained to 60° horizontally and 30° vertically) but maybe eye tracking could allow you to create a comfortable loupe of that size that naturally pans over the page as you look around.