The feature is available in X-Cart 5.0.x-5.3.x
The Disable Drag-n-Drop Add to Cart add-on disables X-Cart's drag-n-drop add to cart feature.
The drag-n-drop add to cart feature enables a shopper to grab a product from a product listing and drag it to a drop location at the top right-hand side of the screen (it says "Drop items here to shop"); when the hold on the product is released, the product is added to the shopping cart:
To disable the drag-n-drop add to cart feature, you need to install the add-on.
No need to configure any settings - it is just the status of the add-on that affects the add to cart behavior (add-on enabled = drag-n-drop is not used; add-on disabled = drag-n-drop is used).