I’m actually surprised you were the first person to bring that up. I was going to, but then I got into a conversation with someone in the thread and forgot. It’s the only time I can remember where they really used the idea that space is three dimensional.

They even make a note of it that Khan is possible to defeat because of it. Spock says, “he is intelligent, but not experienced. His pattern indicates two dimensional thinking.”

And then virtually all other Star Trek space battles are based on two dimensional thinking. Oh well.