Yes, it will automatically update. Whether you can then exit the file and when it asks if you want to Save and you choose NO and it goes back to the way it was originally filed.....Im not sure.

I just have a printed copy of the original on hand to refer back to.

Thank you Lisa.

That was my understanding so far and I have made .pdf of each return. Its just that the original return is easier to use for analysis and especially if you want to use it to do a proforma for the next tax year and save the proforma under a different name. 

Don't see why it should update if you don't save it again???  Oh well.