Hey, I wanted to propose a mindset for thinking about what you should learn, instead of a particular skill or domain. Thinking about what you should learn to benefit your employer is nice, I'd think more about what skill you could learn that would help you most over the next ten years, for job satisfaction, income, life quality, etc. Something fun, which also makes you more valuable in the marketplace, sounds like the way to go. Anyway, having a manager that looks for feedback on stuff like this, sounds like a good problem to have.
I like this article on skill-stacking, might be a frame you think is good, maybe not.
https://forge.medium.com/how-to-become-the-best-in-the-world...
Read Revelation Space by Reynolds and Pandora's Star by Hamilton if you feel like you exhausted SciFi. Also check out The Diamond Age by Stephenson and Altered Carbon by Morgan if Snow Crash isn't for you. Stranger in a Strange Land, Fahrenheit 451, and The Martian Chronicles are great golden age SciFi
RIP