I have a site where the owners want to stop customers from ordering more than 1 type of item.
The Twig logic is already in place to stop any forms showing that would allow customers adding more than type, which is fine for when navigating between pages. If a customer opens a product on several tabs, they can add multiples of the product.
I had gone through the route listening for the
EVENT_BEFORE_ADD_LINE_ITEM, but I think this isn't occurring as once a product is added to the cart any further products of this type aren't new line items, they are quantity changes.
Is there an event to listen to for quantity changes for the cart?