I've noticed that after a quick save and reload, the chest contents only change once.
While exploring the basement of the tavern/inn, I had a quick save before solving the gas/fireball trap and then another right before opening the superior chest. I opened the chest and disliked the contents. Quick Load my save and opened the chest again -- different contents but nothing I particularly wanted. Quick Load again and opened the chest -- same contents as second attempt. I repeated this another 4 times but the contents remained the same (as the second attempt) each time.
I then Loaded my Quick Save before solving the room, opened the chest and had a new set of contents... but I still didnt want any of it. Loaded that same save, completed the room again and had a forth set of items. So I thought maybe it had to do with Quick Load versus Load.
Performed a Load on the original Quick Save but received the same contents as attempt number 2... So it seems like if I save a certain distance away or maybe if I save far enough back in the solution process, then I can still randomize the loot.
Sorry if that was confusing. Anyone have any solid game mechanics to chest loot?