Slight Spoiler Warning:
Mike Pondsmith has essentially confirmed that V’s immunity to cyberpsychosis comes from the Relic acting as a sort of buffer, absorbing the psychological strain of excessive cyberware usage.
That creates a problem for the sequel, if the next protagonist doesn’t have a relic of their own, how will they justify them loading up on chrome without going cyberpsycho? Even David who SPOILERS: had an unnaturally high tolerance for cyberware usage, ultimately fell victim to it in the end
The solution is to add a new Cyberpsychosis stat.
Cyberware would feel far more meaningful and transformative, forcing you to walk a constant line between having more power and keeping your sanity intact. To balance this, implants would need a significant buff to make the risk feel worth it. You could have Immuno blockers as a consumable item to temporarily stave off the effects.
At higher levels of Cyberpsychosis, you could unlock unique dialogue options (similar to attributes). Questlines could become more unpredictable, for example: you could have moments where the screen cuts to black, only for you to wake up surrounded by bodies. Your mental state could actually impact the narrative itself, with certain endings being tied to your cyberpsychosis level.
I think this would add a ton of depth to the story and gameplay. Cyberware would feel less like typical video game upgrades and more true to what it is like in the Cyberpunk universe.