It would be great if the Constructor could drop stacks of items if a Stack upgrade was put into it. When set to redstone mode, a simple button push could dispense a stack of Ender Pearls, for example. Mixing button types (pulse length) and Speed upgrades could give different results (perhaps you want 2 stacks dispensed on a single button push).

On the same note, a Destructor picking up stacks (like a hopper) would be great too.

Destructor can already pick up stacks.