I was writing on someone else's post about getting banned and I started brainstorming a solution and honestly, if someone who was good enough at coding could create something like this then I would extremely grateful.
The idea is a program/application which uses a bot account which you add as a friend on league, then (hopefully if this blows up) everyone in your game will have downloaded the application and added the bot. In-game you can /w the bot and the bot would then automatically message all the players in your team the thing that you sent the bot, thus bypassing Riot's system, this way we would be able to say whatever we wanted and have no way of Riot banning us.
You would need some knowledge of coding but this solution seems really good, you could also do "/w (bot's name) /all" and that way speak to the enemy team without getting banned.
Another idea which could work is to just create a chat window application that tracks all the players in your game and then adds them to the chat. Then you can unbind the league chat and bind this new application to enter so it appears up on your screen whenever you press it (alt-tabbing league and opening the application over the league window).
The second one would be really good because there is less command typing but either would be amazing if anyone could manage to make something like this.