Make Unique Collection Tab Stackable?

As a casual n00b hoarder that plays 90% on Standard, I already bought 2 Unique Collection tabs at release (even if they are "useless" regarding proper linking them on forum), because I knew I would keep at least the best version of a legacy item and the best current version.

If they would allow us to merge all Unique Collection tab, that would be a great incentive for making me wanting to have a few more, but as they currently forgot that rings should be have 2 slots, or that they should have added specific slots for legacy versions of items, I'm actually not that content to spend on such further tabs.

Meanwhile, a fossil + resonator tab is more than mandatory if you're serious about delving...