Basically , a bot that will remind you IN GAME to stay positive , and that would tell any player that tried to send "are you sure you want to send that ? it doesn't sound very nice to say"
Player will be able to click on the chat to send the message (in case of false positive)
and therefore, since people would have been warned, toxicity shown toward someone that has reported you should be punished harder (i don't ask for 14 days ban , but general chat bans)
Or this feature can be instored to people not toxic enough to be punished.
Basically this is how it could be :
rank 0 :Normal basic chat -> too toxic , you rank up
rank 1 : Bot filtered chat
rank 1.1 : No false positive button filtered chat -> you try to go around, you rank up
rank 2 : Chat restricted 3,7,15,31,63,127
rank 3 : Obligation to take a video lesson before playing again (and test to validate they understood, this only happen once per account and does reset every time riot's policy change)
rank 4 : Ban 1 day
Rank 5 : Ban 14 days + honor Drop
Rank 6 : Ban Pemanent
Rank 7 : ID Ban
Basically this will avoid the "surprise 14 days ban"
And may allow you to tighten a little more the rules.