It works for chat because you're trying to change behavior, not learn a skill.
Intentional feeding is a behavior. Non-intentional feeding is a behavior. Typing is a skill. Communication is a skill. This is not the correct thread to discuss this. I'm backing out of this topic. Get your responses in but I can't discuss any further in this thread.
There have been times where I have died, run back to lane, seen my ADC in a jam and run in to help, dying a second time in short order.
If the ADC died, you gave 3 deaths.
If the ADC lived, you gave 2 deaths.
If you let the ADC die, you gave 2 deaths.
Not saying you were doing anything wrong or right. Just pointing out that the passive play would have had the same result as your "noble sacrifce". Support lives matter damnit.
The point is that intentional feeding is about intent, which is often difficult to discern.
Then let's stop trying to discern. Non-intentional feeding is just as detrimental to the team as intentional feeding.
Or, we could use tiers to discern.
For example, you are feeding in a ranked game. You are suspended from ranked games until you complete X normal games without feeding. If you feed in the normal games, you are suspended from normal and ranked until you complete X intermediate bot games without feeding. If you can't complete X bot games without feeding then you move to beginner bot games. If you can't complete beginner bot games, then you are intentionally feeding or so bad you are a detriment to every team you would play on. Leave them in beginner bot games as a sort of "prisoners island".