Make Accurate Reporting Affect Honor
A history of making accurate reports should contribute to your honor, and making too many inaccurate reports should reduce it. This would incentivize reporting while also punishing over-reporting.
We should also add a public 'creep score' of the number of players punished due to your reporting appear. It would appear in the honor flair, which should be granted for the next game after a successful report, if you received an instant feedback report last game. This change would give dutiful reporters something to be proud of, while also deterring bad behavior by reminding would-be toxic players that they are being watched.
Personally, I already love reporting toxic players and getting instant feedback reports, and these changes would make it even more fun and rewarding. Getting the little thank-you flair would definitely help me feel better after whatever toxic thing happened, and seeing my CS number tick upward over a season would remind me of the good I have done.