I suggest that you consider adding a VPN blocker and A Proxy blocker as an Addon mainly for servers centered mainly around PVP it would be a huge asset so people aren't able to come back after getting IP Banned. There are so many instances where it's the same person just going on a VPN/Proxy and an alt and just repeatedly coming back to cheat and because you can buy over hundreds of Alts for next to nothing it's a never-ending cycle.
Yes, I'm aware there're ways around a VPN blocker and a proxy blocker but it will make it almost impossible for the average person to come back which will also, in the end, deter people from hacking in general knowing that they cannot return to the server ever again.
https://www.spigotmc.org/resources/anti-vpn.58291/
https://www.spigotmc.org/resources/stopproxy-protect-your-server-from-proxies-bots.19653/