I am preparing several years of late Form 990-Ts for client. I started with the earliest year and rolled forward (transferred) proforma info to the next year as the returns were completed. Now I have received new information for one of the interim years but when I make the change I will need to roll forward (transfer) the proforma info to the next year (which is 99% complete) because if affects a carryforward. 

Will transferring the 2020 proforma to 2021 again delete all the 2021 information that has already been entered?