Stackable items need to go beyond 10.

The new stash affinities are great but stackables (ex. runes, essences, expedition currency, etc.) need to be able to stack beyond 10. If you put any of those stackable items into the slots at the bottom of the currency tab, they stack well beyond 10, so I don't see why they have a hard limit at stacking to 10 except to promote buying stash tabs since you quickly run out of inventory space.

they will, once they add the actual stash tabs that they can sell you.