Why they shouldn`t be stackable and act as mini-bins?
Once u fill wooden box with stuff of same type (15 sinews for example) u can build another one on top of it by adding same material (5 fresh boards and 4 wooden plugs) + cotton/leather.
Lower one get closed and new 15 slots open but they can be filled only with item identical to first one (bins mechanic, first item define content).
They become un-movable after stacking.
After it get filled u need to close it again with same cloth/leather to become finnished stack or add more boards/plugs to raise to another level, up to maximum 3.
U cant add/take anything from finnished stack without breaking it and pick what u put in it (Bees-skep mechanic).
This mechanic will add cheap low-lvl storage that conserve space on small or temporary claims like hunting cabins. 3 layer stack will give you 45 slots storage unit against next in line (25 slots chest) but without conformity of transporting it in anyway once you start to stack them.