Awesome, thanks @dmertz !
To confirm my steps here:
a) Amend 2018 tax return by including 2019 1099-R form. Ensure the amount from 2a on the 1099 is on line 4b on the 1040 form.
b) TurboTax will ignore this form if I have code JP and no amount of tax withholding (this is the case for me). Therefore, is there a downside to including it? It feels like including it would at least keep loose ends tidied since it ignores it anyways.
