I like this idea, but with a few improvements. I agree that it would be quite inbalanced if a whole player's loot drops right behind you after you hit them into the void.
What happens if a player falls into the void by themselves? What determines who gets the loot spawned behind them if multiple people attack the same person?
My suggestion is, void loot is "dropped" as a loot package at a random/nearby location on the map. This would allow anyone to loot the player's body.
View attachment 154119
Once it drops, it would look like this:
View attachment 154120
However, to add more challenge, the loot package could just fly across the map, and require players to shoot down the chicken(s) to then have the chest drop. This could be done with an invisible bat, or movement of the chicken.
With keeping pure skywars though, if you decide to knock a player off the map, then you shouldn't get the loot. I wouldn't mind it either way.