So, yeah. I've been farming seals in Von1 and rerolling the Epic chest trying to get both more fragments and a Seal of ESOS.
Upon rolling my latest reroll of the chest, a message pops up "You have ransacked this chest often."
I feel this is rather terrible. Not only do you lose the loot from the first pick, but it costs you Shards to do so. So instead of getting 10 loots, you get 5 if you reroll trying to get a Seal.