I think this topic has been chatted about already (Alt f4 - #26 by Jonboy).
I don’t have a golden bullet solution. But I can imagine running in to a fight with a bot who then just suddenly drops to the ground and needs rescuing because the player reconnected. Bots are admittedly pretty bad and nobody relies on them to keep them alive, but that experience would just be jarring for those NOT doing the alt-f4 thing. Backs to the wall sharing aggro, and then suddenly it’s all on you.
Better all round if the game could capture alt-f4 and record it so that the round can’t count for progress. I’m pretty sure the 10-games-no-down malice+ steam unlock (“Flawless Execution”) used to discount a round unless you got all the way through, start to finish, no outs so I’m not sure what’s up with this newer one.