How can I do Lot Tracking in ItemPath?

To do Lot Tracking, treat a Lot like a one-use virtual container.
Set up an Item Type for a Lot.
The "container" which represents a Lot is an item with its own Item ID.
Then record the inputs into the Lot using the Combine check-in into an Item with the ID for that Lot.
The items that are outputs from the Lot can be new items by using the Create From Item, where the parent Item ID is the Lot's ID.
That way you will have Lot tracking with the ability to tie output items to the input items.