Hope this hasn't already been posted, if it has, apologies in advance... just with Vengeance working on inventory.. I thought it was worth mentioning...
I notice when I'm smelting gold and making ingots, there's a lot of clicking involved, even just to select quantities, which in many cases is a single ore (for making an ingot).
It'd make things easier if ctrl+click picked up one item from the stack and shift+click picked up all... with both bypassing the quantity window.
It may not sound like much but when you add up all the clicks and all the mouse-movements to move to the slider accurately, etc... it equates to a lot of unnecessary clicking and cognitive processing.
Just a thought.