I just switched my Elementalist from Carrion to Berserker gear. But I don’t want to get rid of the Carrion gear in case I decide to switch back. But it’s also taking up 6 slots to keep that gear in my bank or inventory.
My suggestion: If you have 6 pieces of gear from the same set, you should be able to combine it into a box – just like the current “Box of <Set> Armor” that crafting professions can make, but instead of making a box out of the combined amount of raw materials needed for the set, you make the box out of the 6 completed pieces of armor.
It could either be implemented as crafting recipes for the respective armor crafting professions, or put in a consumable item that will let anyone turn 6 pieces of set armor into a box. And of course, if any one piece of armor used to make the box is soul/account bound, the box will be too.