Changing the size of chests (Wood, Iron, Steel, Logistics Storage). Providing more storage space, but increased the recipe cost.
Mods introducing new content into the game.
More than just chests.
Why not Mk III, IV etc.... Chests can be defined like : "Mark" x "Used material" = avalaible slots
Mark I II III IV V etc... can be all the same number for every chest and material a multiplicator
Wood < Stone < Brick < Copper < Iron < Steel < Plastic < ....
Well i might think about it :D