So, i have a customer request to be able to fill in a form, save it (which creates the line item ID)..but leaves the form open with the fields still populated, edit it and then save the newly edited data and save that as a new line item.

Example: User has to submit 10 separate submissions but some of the fields for each submission would be the same. To save time we need to let the user save one submission after another without closing the form but also creating new ID's for each time they "save". 

the "save and continue" button gets me close to my solution except that that button continues to edit on the same line item...i need it to save and create a new line item without clearing the fields on the form. if that makes sense?

This form is still in works so excuse the messy layout but just to provide a screenshot example:

so, every field that has data would stay populated after they hit save and only the fields with the red arrows would need to get edited and then submit again as a new line item...continued on for how ever many submissions they need to make whether it be 10 or 100.