As far as this module goes, the added column in the orders table, is basically just good for tracking what site of your multisites the customer checked out on. It's great to have a multi-site module that allows customers to buy from multiple shops and domains in one transaction, but what about tracking which product came from where? If different shops are run by different people, one (I) needs to track which merchant(s) to credit for the sale. Is this possible or is it asking way too much of the module and perhaps zen-cart in general?