how about additional symptoms in 1.0? bc the potential is immense, for example actual dog bites that just look different than infected bites, since they always say that "the dog bit them", there could be different degree burns, skin conditions etc.
you can also approach the whole thing holisticaly, like you know by each system, circulatory and immune are well made but we can have them like twitch randomly, speak in a distorted fashion from nervous system damage (there could also be a tutorial prompt like "a survivor with blunt force trauma to the head can speak in distorted fashion, but it can also be a sign of infection" and add like bruises and bumps on the head, that would correlate to that and make it ambiguous) , urinate from urinary system muscles shutting down (or from fear), or like have their bowel movements stop from gastric system shutting down.
Also having additional cash for spotting details, even those unrelated to the virus would be cool, like you get basic 350 for just directing a correct survivor to the block, and additional 50 per disease symptom, since technicaly you would make the medic's job easier. the feedback could be given at the end of the day like that screen which shows if you screwed up and let an infected guy in. im hyped as hell, id be stoked if you'd let me treat their conditions in the med bay as well, or just let me diagnose them by comparing symptoms to the list of other diseases, and increase the reward for evacuating a 100% healthy survivor with no additional diseases.