Typically, we don't want the customers to choose inventories manually as the extra steps might lead to an abandoned purchase.
However, when the inventories are managed automatically, sometimes the items in one order might be shipped out from different inventories.
In this case, the customer should be informed on the cart page.
This is very important, especially for international business, because customers from some locations like the EU might need to pay for the importing duties if the items are shipped from countries outside the EU.
