Pressing "merge -> split one -> merge" in quick enough succession duplicates stacked cards

[Balallalalalalalalallllalalalalalaaalaa]

With a stack of negative consumables of size 3 or greater it is possible get a stack of size 2x - 1 of the original by splitting one off then selecting the larger stack and rapidly clicking "merge -> split one -> merge". This allows you to duplicate the cards until you reach the stack limit of 9999

The increased number of consumable slots is due to a previously reported bug where spliting one from a stack gives an additional consumable slot.