I just realized what'd be great place to explore the past of Jackpointers. The novels!
I've read through Frost and Fire, I started Dark Resonance, and am working through Borrowed Time now.
So two of these are about Jackpointers. Frost and Fire follows Elijah around and Borrowed Time followed Winterhawk. And you know what's annoying, they don't go into these Street Legends' past at all. It's implied. But I learn way more about them from Street Legends, then I did from those novels. And that's kind of a shortcoming of the novels. It's great for capturing some of their personality, like Elijah being a complete jerk when he's focused on uncovering some ancient arcane thing, or Winterhawk being kind of full of himself. But what these guys did before the books? I got no idea.
Can the novels be like mini narrative heavy source books on Jackpointers? That'd be pretty cool in my humble opinion.