In case someone doesn’t know (and that would make me feel guilty).
So, the two red chests in the room which opens after you beat Jackpot the Jack’s Bot always re-spawn after restart, no matter the character (on PC).
You also get a lot of money and an eriduim chest, not to mention the loot from the boss.
If you have a corrosive Anarchy, it will just melt Jackpot the Jack’s Bot, because you have to kill a lot of loaders between the phases, so it’s a very fast farm.