Hopefully this doesn’t count as spoilery, but your guess as to what’s up with Zigzag is as good as ours. As far as I know, Wildbow has never commented on that. Whoever they were, they’re dead now, so it’s not really relevant to the story.
Yeah, that’s fair enough.
I kinda like this, honestly. The fact that Wildbow puts in things like these that are intriguing, but not relevant and not promising to be relevant (which would make them an annoying violation of Chekhov’s gun and conservation of detail)… details that indicate that there’s a story here, a story we might not ever learn, much like how we see traces of strangers’ stories all the time in real life. It makes the world feel more real.