Serial Numbers on Products and Stock Moves

Of course lot is for traceability but it is the first level. It tracks just the lot.
If you want to add the production tracebaility (when some lots are merged in a new lot), we need to have a view like discussed here: Redirecting to Google Groups

No, this is clearly a product (or variant) with a product code

Here the argumentation is about the fact that serial number or lots are the same. It is only a matter of limitation on the quantity.