One aspect of the setting that is easy to forget is just how much was lost. And one of the best ways of making it real to the players is to occasionally remind them of who they have lost.
A simple trick is to roll a D2/flip a coin for each family member to see whether they survived. While the average survival probability was lower, family members likely have a partially correlated survival, and if the PC is alive then the chance that their family survived goes up a bit. But it is very likely that any PC has lost spouses, parents, siblings or children.
One way of using this is to just "accidentally" mention it: "The captain reminds you of Marla...", "For a moment you thought the kid was little Benny, but then you realize it is just a neotenic. Benny was in London..."
In fact, handling Fall trauma is a big an interesting topic on its own. The edited memories of infugees are largely a quick and dirty way of avoiding mental breakdowns as they recall the horror of the end of the world. But even lucky people lost much, and handling all that grief keeps many Muses, psychotherapists and pharmacologists busy. I suspect anti-PTSD treatments might be very common, and deliberate emotional memory weakening fairly standard:
"Today is our anniversary. I cherish the memories of our family, remembering all the good times. I remember the bad times too, but without colour. The new house in Xien He, the laughter of Ling - I can see and hear them in perfect detail. The flight from the city, the crushing crowd as the machines started to descend, your scream, waking up inside the cordon - I recall them as objective facts, with no emotion. Even the process that led me to do the edit is just a fact: I could not function as a human, so the source of the pain was modified. When I look back at those days of uncontrollable crying I only feel relief that they ended so my life could begin again. I am sad the others are not here with me, but I have my colourful memories. They live in them."
This suggests an interesting subplot for an adventure: a key person has undergone this kind of trauma dampening psychosurgery. If someone could get the original psychosurgery files they would have an excellent mental weapon against the person. There might be a trigger that unravels the dampening, allowing the grief to return - and maybe it could be amplified.
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Mea Culpa: My mode of speech can make others feel uninvited to argue or participate. This is the EXACT opposite of what I intend when I post.