Performance-based roll system

[Yeol]

I would say keep rolling numbers independent from performance. But we can reward the entire party with extra loot to roll on at the end of the fight if they clear it with no deaths.

Clear with deaths = 4 items.
Clear with no deaths = 5 items.
We can be generous and say no more than 2 deaths = 5 items.
This is in case of normal 8 man raid.

I don't think people will stress out and kick other players in order to get the 5th chest. Because in the end, they might not win any loot, it's still RNG.
The extra chest is only there encourage people to play better.