Infection system rebalance
As far as i know, currently it's just a flat chance different for scratch/laceration/bite to get infected which is kinda boring considering new IWBMS zombies are quite deadly even without infection on, and now you get attack speed/movement penalties depending on wounds, which is fun on its own since you actually get to use medical system, but you will probably not get to experience it after drinking bleach because there's no hope once you get infected from an attack.
Lorewise players are immune to airborne form of virus, so why not give them more chances at survival, its their death story anyway, why not prolong it for more !!fun!!
What if players would have hidden(or not) immune system meter which at 100% would cut chances to get infected by flat 50% from all wounds, but getting scratched/bit/lacerated lowers immunity by some amount so you get less and less resistance (linear graph type), and your infection chance at 0% immunity goes back to current 5% for scratch 33% for laceration and 100% for a bite (or even higher for every type of damage than it is now) as well as making player way more vulunerable to regular diseases (flu, food poisoning, etc) as well as making it harder to deal with them.
If immunity is somewhere above 60%, when roll for infection passes, players instead get sick with a very bad case of virus (there was some book where in zombie apocalypse survivors had complete immunity, but they still would get infected with dysenteria, blood rot, botulism all that stuff because of how nasty zombies are, its just for lore reasoning, no need to code each illness in), its possible to recover from that over time, but really hard and if players survive that initial sickness, they still have to deal with endurance, strength and speed penalties that go away after few weeks(months?).
Maybe make immunity recover very slowly on its own (new traits related to this?), which would be aided by good diet (we get to use all the other unused food values in here) and antibiotics.
What this will do is make deaths less rng, make it possible to die to bleedings/infections and make players actually play the game after they get sick moodlet post laceration.
You still can't get careless since if you get grouped you just die to wounds, and if you survive that, your lowered immunity will make you vulunerable to flu AND you get high chance to get infected from all raised infection rolls.