Got it. Thanks for the response and info.
Yeah there are other issues with IP banning that are even more common such as mobile carrier IPs, single IPs can be shared by very large amounts of people simultaneously and shared by a huge amount of people throughout the day.
IP banning imo is somewhat a last resort and should mainly be used on dirty IPs that are unlikely to have any legit users.
I see what you mean in regards to allowing usage, but preventing sign ups. Last I checked, the IP bans also prevented sign in to existing accounts. I still think disallowing posting from banned IPs would make more sense than it wouldn’t.
Time based IP bans could be a good idea also, e.g. banning an IP for 30 days to prevent overly-broad destructive bans staying forever by default.