rkierski, no you do not enter any amount there. That question is asking if you did a return of contribution, not a recharacterization. You'll need to go back and correct the amount you entered as the amount recharacterized to show the total recharacterized. (When entering the amount recharacterized, do not include the amount of gains included in the transfer.)
No, you will not receive any updated 2019 Forms 1099-R or 5498. You'll receive a code R 2020 Form 1099-R reporting the amount of your 2019 contribution recharacterized in 2020. If you enter the code R Form 1099-R into 2020 TurboTax TurboTax will remind you that the recharacterization should have been reflected on your 2020 tax return. Since you will have done that, you can ignore the code R 2020 Form 1099-R when you receive it. You'll also receive a 2020 Form 5498 showing the recharacterization contribution to the traditional IRA.
Gain attributable to a recharacterization do not affect your tax return in any way. They simply change from being gains in the Roth IRA to being gains in the traditional IRA.
