or maybe a better idea:

People who have started an empy weapon and are on trial 1 of the 50x items, just CAN'T do anything else after it's completed to do trial 2 x50items and then trial 3 x75 items, right? Well if the moogle can just be nice enough, bc it knows we don't go on an other path after one is done, to make us 'give' our tier 1 to tier 3 items to the crate already, regardless on which of the 3 we are, then we can already 'work' on the trials ahead without loosing time or space,.... maybe an idea? then we don't have to make them stackable if that is too much work =)