I believe your position is incorrect and I am just trying to help this doesn’t happens to other people or myself in the future. I for instance will be super careful if buying next time cause that cart looks dangerous and tricky. That use case of people buying more than one item should be the least common and a warning will not prevent a customer from buying.
Sort like “do you want to save your work before closing this app”.
Another option is, users can configure their cart so that their specific cart doesn’t behaves so misleading. I would do it right away cause currently I don’t trust it. And I am very unlikely to buy two licenses at any given time.
Customer care would save lots of extra effort, sellers will get less refunds, you would get less disputes and customers less time having trouble. I fortunately had more money to buy the item I was missing otherwise would have to just be jammed. I am still jammed since I don’t know what would happen or would require total refund and then later repurchase. I haven’t downloaded any of the two items which is stopping me from continuing my work.
Another thing I noticed is that I had in my cart another item likely added months ago, when tried to purchase the last time. That cart doesn’t forgets. This is another source of mistakes. I had to empty my cart since I was already super careful with it. Misleading.