Helping the 4v5 problem
People have often asked lost 4v5s to not be counted as ranked losses, to be treated as loss prevented. The counterargument against that is that it could be abusable in order to gain ranks by preventing any LP loss at all.
So my idea is to do the opposite: If a team WINS a 4v5 with the DC'd player having disconnected at least 5 minutes prior to the win, then they get 2/2.5x the LP.
Would this fix the problem? No. But it would make dealing with 4v5s less frustrating as they would no longer be seen as a free loss, and instead a more high risk high reward situation. Can your team manage to win the 4v5, are you good enough? If yes, then you deserve to get a large boost in LP imo. Lose? Normal LP loss. And of course the DC gets punished with 2/3x the normal LP loss regardless of whether the team won in the end or not.
Chance of loss is higher, so rewards for winning should also be higher, no?