Chat Restriction Alternative
Trying to communicate in ranked with one message per 4 minutes can be very frustrating, considering lack of communication is what kills teams. Allow players to speak more often, but prevent them from forming long messages. It will allow them to communicate smaller, non-pingable things such as "Can I have blue?" "[x] flash down." or "[x] teleport down."
Of course, players will be able to lower cooldowns on messages, but that's where a revisioned ban system comes in.
Give them a one week ban or something for abusing the chat-system.
"But the toxic players gon' be toxic n' spammin'."
You're wrong, not every player who has a chat restriction is going to be toxic or spam. This will make communication in ranked so much easier while having the potential to teach players to not talk so much.
The cooldowns should stack to 5 like normal, but add a message every 90 seconds and give them a limit of something like 20 characters per message.