Try the edit button. I grant you that if you reduce your holding by 20 shares you need to decide which of your entries you want to edit. But it really does not seem like a difficult point.
Can you? As far as I can see you can track currency exchange movements but you cannot track currency holdings (No edit button for quantity. Just row delete). Or to be more accurate you can track Cryptocurrency holdings but it is not obvious to me how to track FIAT currency holdings.
