Lets say you have 1 type of stackable item in your bag, like Metal spikes.
Then you have no slots open.
Going around gathering and only getting something if you have metal spikes and it auto stacking isnt a good option. I think you should have to have room in your bag and sort through what you want or dont want and it auto stack things in there.
This way would make it easier for people to macro and or bot too.
Current way is good, just needs a better overall inventory system IMO. The boxes are a bother. I like UO/DFO with a Wurm system of how much volume the item has.
IE you cant put a rake in a backpack but you can put it on your back. You could carry 100kg of cotton but it would be so bulky you couldnt fit it into backpack.
But you could carry 200 needles in a small purse or something. Understand?