Obviously I can't answer how long Google should block an abusive IP address since I'm not Google.
A CGNAT IP address is not reassigned to a home, it's shared among many homes. If you meant from my example the cloud server IP, that is one issue that comes up pretty often on cloud services and there's not a clean way around it.
For example I use Linode as my VPN server, I used to have all sorts of trouble with Google making me enter captchas or blocking my search just because of the abuse coming from the same IP range. I actually can't even login to some apps while on my VPN, and I've had this same IP address on my Linode for close to 10 years, so it's not an issue with my /32 specifically.
You'll see the same thing on AWS, many of those ec2 instances can't be used for sending email or for VPN services because previous users of the IP space abused their way onto block lists.
A CGNAT IP address is not reassigned to a home, it's shared among many homes. If you meant from my example the cloud server IP, that is one issue that comes up pretty often on cloud services and there's not a clean way around it.
For example I use Linode as my VPN server, I used to have all sorts of trouble with Google making me enter captchas or blocking my search just because of the abuse coming from the same IP range. I actually can't even login to some apps while on my VPN, and I've had this same IP address on my Linode for close to 10 years, so it's not an issue with my /32 specifically.
You'll see the same thing on AWS, many of those ec2 instances can't be used for sending email or for VPN services because previous users of the IP space abused their way onto block lists.