Roth IRA earnings on excess contributions: amend early?

I withdrew in early 2020 some excess Roth IRA contributions made in and for 2019, and corresponding earnings on this contribution, but I did not include the taxable earnings in my 2019 tax return. So I need to amend this return.

 

I read elsewhere on this forum that one usually files the amended return when the 1099R is received the following year.

 

However, since I already know the content of box 1 and 2a for the upcoming 1099R based on what my bank returned (and I confirmed the earnings amount independently using the Worksheet 1-4 formula in Pub. 590-A, so quite confident it is correct), I am wondering if  there is any caveat in filing an amended return now, with code J8 (in TT 2019 amendment software) , and then ignore the 1099R next year. 

 

Thanks. 

 

PS: I will also be removing 2017 and 2018 excess contributions later in the year (and file corresponding 5329 forms for the 6% penalty), but as I understand it that should not have any bearing on amending my 2019 tax return.