Adding a lot numbered item in multiple lines on Same order

Hi Experts,

This is a very unique issue we face and it is important in our operations. When we create an order with the same item in multiple lines, we noticed that NetSuite does not reduce the item qty coz. Which means that in case of lot numbered items, if the available qty is lesser than ordered qty, the error is only given after hitting save which in turn causes the complete order lines to disappear. Check screenshots below for the order example & error.

Our orders line are in the access of 70 or 100 at times and most times these are entered manually by field sales as they take orders from customers. Our sales reps also key in lot numbers on the sales orders when they create orders & it becomes particularly annoying an unproductive when the system fails to give the error for not enough stock if the same item is keyed in multiple lines along with lot numbers & the error page also results in all the items keyed in being lost.