Ok, I was asking because with what we know (think we know) it shouldn't influence the drops.
However (but that's just a theory of mine) :
-the chests are generated when the instance is created (i'm 100% sure of that)
-The items contained in the chests, and the order they will drop is also determined when you enter the map (the fact you can drop 2-3-... of the same tome when you group with several players/chars and "empty" the chest make me think this way. There isn't a dice roll everytime someone open the chest)
-The items drop rate (especially shields) could be higher than we thought IF my second point is valid ( shields drop rates are around 4-5% usually) but it could be more in the scenario of 8 players/chars open the chest(s). (but it doesn't change the chance of 1 player getting a shield, just the drop rate)
Most of the datas we have are from 1 char opening the chests
What if 8 toons open the chests ?