Troll players freezing servers with chat

The damn players a found a way to freeze the servers.
We figured out a way to filter so it only allows up to 150 characters and chat but for some reason it still goes through and it will freeze a server and there's some rogue players going around freezing a bunch of servers including mine is there anyway to fix this?
Here's what they're using but a lot
XOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXOXO

 

The new ChatHandler version i'll push after todays Rust patch will have options to limit characters sent per message.

 

Awsome thanks.