Idea: Add a way/tip to make new players know how to chat, so whenever a new player joins a game for the first time/didn’t type any message, a small text would appear at bottom of screen saying, “Press T to chat with other players!”.
Another Idea: Whenever a player joins a mission which has a higher tier requirement than their tier, a warning would appear that the mission may be harder and try to pick an easier one.
Also, can you check this topic? Custom emojis are already wanted.