If you think you are safe, you do not need to make estimated payments. If you do end up owing, yes, you will probably be charged a penalty. If you wish, just make one smaller payment early and omit the rest.
Just because the unemployment has been deemed excludable, that does not mean it will be a MAGI adjustment for other purposes. The Bill reads:
(1) IN GENERAL.—In the case of any taxable year beginning in 2020, if the adjusted gross income of the taxpayer for such taxable year is less than $150,000, the gross income of such taxpayer shall not include so much of the unemployment compensation received by such taxpayer (or, in the case of a joint return, received by each spouse) as does not exceed $10,200. “(2) APPLICATION.—For purposes of paragraph (1), the adjusted gross income of the taxpayer shall be determined—
“(A) after application of sections 86, 135, 137, 219, 221, 222, and 469, and
“(B) without regard to this section.”.
Code 222
