I think at most, the best possibility would be to reduce the last chest in a dungeon to a 1min timer rather than 5. Then people wouldn't be able to test peoples patience and it wouldn't be as bad. Not sure how hard it would be to implement but something as simple as "These chest are 5 minutes except when opening final boss chest which is set to 1 minute now" Because it makes sense to have it 5 mins on the first few because there is forward momentum but when you get to that last boss/chest there is no excuse as to why people wouldn't be aware of the loot upon completing the instance.