Book tests are tricky. It's easy to fall into the habit of "just saying nouns" as Teller puts it.
So, I think the first thing to do is decide what you are demonstrating. What "power" as it were. This determines how the reveals are done to best effect. This will also determine which methods are acceptable and which are not.
Personally I focus most of my presentations around energy and connecting to people via energy, coupled with a deep understanding of the human condition. This allows me to start reveals with a vague idea, then narrow it down like a camera coming into focus, and then try to nail the final reveal with an educated guess.
So what are you demonstrating?
The way I do a book test currently, which is not my ideal and I doubt it's unique to me, I end up revealing 3 or 4 things. I use a book called Atlas Obscura, which ties into my obsession with oddness and mysteries, and I have a random number generated that's very long. From that number we take pages, and the person reads over the page and I tell them what they are seeing. But I don't just say, "You're looking at the Fiji Mermaid, aren't you?" I start with feelings and impressions, then work in some imagery, maybe talk about a memory it might remind them of, and finally give a vague but accurate enough description of the image on the page and what it is. The second reveal gets more detailed, and the last one I try to get exact. It's a build up, and demonstrates an increasingly strong connection with the volunteer.
The problem with trying to do multiple reveals with a method like Gatsby is that you're just getting 3 words. It's more work to build a reveal around a single word, particularly if you're doing multiple reveals. If you nail the reveal on the first try, each successive reveal is less impressive, because you're just repeating yourself. Even changing up how the reveal is ultimately presented, unless you have a good reason for it, is still just revealing the word. With single word reveals like the Gatsby method does, I only do one reveal, because ultimately that's more impressive.