mynameisss

You can apply a one way function to an IP to obtain an ID and then maintain a database of bad IDs. For example you could compute this ID by the SHA256(IP + secret salt). Since way one function don't allow you to recover the IP, the ID is not PII. If you detect an IP which has bad ID the connecting ban that IP from the game. I think this respect the GDPR, you don't maintain a list of IPs or any other PII.

Instead of using an IP address to identify cheaters the game could assign a unique random generated ID to players. Then they could ban that id without using IP. I think this scheme complies with the GDPR if you take care of not binding that ID with other user personal information.

your question: higher levels of beta amyloid would correlate with lower levels of virus. A metaphor for answering it: if the protection arrives late and the harm is done then the number of protectors can't be used to predict the harm. So to anaylize the correlation one has to know if the effect of the protection happen before it makes the harm or not. That is the speed here is an essential ingredient. Emperator caveat: I applied abstract reasoning and a metaphor, don't know about the specific details of how beta amyloid is generated.