LP Gain and Loss Suggestion
If LP loss and gain was proportional to the players active I think it would be better balanced, and a reasonable contribution for the effort placed. For example. If 4 players disconnect and 2 players remain somehow by some ingenious plan they should both collect the same total of the LP the players that disconnected would have got.
However if they still lose they players that went AFK or disconnected would be penalized normally but they would take 1/5 or 1/3 LP loss to cover for the players that decided to still play. Those players that remained would pay the loss in LP - 1/5 or 1/3 total. As a bonus you could display how many LP was saved or LP that was gained as a bonus.
Showing this type of dedication to the player base would also bolster morale. I know that the community can sometimes be toxic in game. Promoting healthy behavior, that sounds like a worthy mission.