How to stop mentions from server like, @everyone @here

Players in my server have found that they can @here and @everyone in global chat and it will ping everyone on my 1000+ person discord to the effect that players will spam the messages back to back. Discord has no way to adjust the permissions of webhook bots so I cant take away its ability to use mentions. I have tried adding the mentions to the BetterChatFilter plugin but it seems discord messages sends the messages "prefilter". If it would be possible to add some sort of update that allows a user to block messages that contain blacklisted words in the config file that would be excellent!

Latest update should no longer mention "@here" and "@everyone"