Mostly correct assumption. I had $75000 moved from a normal IRA to a ROTH in May of 2021 and electronically transfered $18000 from another non IRA account to the the IRS (May 16) to PRE PAY the tax. BUT, TURBOTAX reduced, by it’s calc, in the form of an $11 penalty, my refund.
If the IRS does not catch this, you owe me $11.
