So while at work I thought up a handful of extra prompts that the staff may consider worth incorporating into the developmental mission event. The list we have as is is pretty solid, but I considered a few extra niche ones that might help flesh out characters in slightly more unexpected ways.
Doubt - Everyone has things that they want to do in their lives, and things they hold dear to them. Everyone is the hero of their own story. But what happens when someone is confronted by a conflicting reality? What really drives people, and what leads them to believe their way is the best one to achieve their goals?
Comfort and Solace - It's hard to go at 100% all the time. Everyone takes time off, and has their own little ways of letting off steam, and feeling like a normal person after all they've been through, and what they have left to do. So what happens when a person's precious and rare times off are interrupted? Or snatched from them? Or what happens when it turns out two people, people who you'd never assume would get along otherwise, share the same hobby?
Trust and Betrayal - It's hard to go it alone. Everyone has someone they feel like they can rely on, or someone they turn to when times get hard. What happens when that person isn't available? How do people react to betrayal, even if it's just the appearance of betrayal? What happens when your friends or comrades start to feel they know better than you what's for your own good?
Myths and Legends - It's a big big world, and there are certain things in it that you just can't go without noticing. Sometimes, the fiction is more real than the real thing. What happens when someone meets their idol, or confronts someone they spent their entire life being afraid of, or running from? What happens when a person finally has to face the superheroes and villains of their mind, in the real world? Sometimes, we realize too late that the things we built up in our own minds were as flimsy as tissue paper.
I doubt they're perfectly viable as is, but they seem like perfectly suitable prompts, given what's already being playtested right now.