LeaveBuster does not required ANY report to work. You get hit with LeaveBuster as soon as you afk for more than 5 minutes before anyone even have a chance to report you post game. Reporting post game then would do nothing because the person already got hit with LeaveBuster.
If 4+ reports would trigger a manual review, you will see a lot more "report xxx ty" being spammed in chat. It would leads to a negative environment and at worst, get other people punished for report calling. If you want someone manually reviewed, you can already send in a support ticket detailing what happened and call attention to the chat where they said they will intentionally afk. Why create a new redundant system that likely ends in negative "report xxx" chat that potentially gets other people punished for something that required 0 report to work? https://support.riotgames.com/hc/en-us is here if you want someone manually reviewed without needed 4+ reports.
You CANNOT visually see Low Priority Queue from someone's match history. It goes without saying that if you stalk his account for a week, you will be able to detect nothing from it and he would still be playing because LB's highest punishment is 20 minutes LPQ. It does not mean he did not get punished for it though, but you will never know it because LB never send feedback notice and it is not possible to know if someone got LPQ.
