A return of excess contribution by the due date of your tax return can be used for anything you want.. The tax treatment of a return of excess contribution is not affected by what you do with the money. Of course if the excess contribution was made through your employer you must include the excess contribution in income because your employer excluded it from the amount in box 1 of your W-2 under the assumption that you were permitted to make this contribution.
Yes, the contributions you have already made for 2020 are similarly excess contributions that must be removed by return of excess contribution before the due date of your 2020 tax return separate from the return of the excess contributions you made for 2019. You can request this as soon as you stop any new additions for 2020.
