There is no penalty on Roth conversions. The result of converting $6,001 when you have $6,000 of basis that TurboTax automatically includes on Form 8606 after you enter your traditional IRA contribution made for 2019 is $1 of taxable income which is included on Form 1040 line 4b. A $1 increase in taxable income is unlikely to change your income tax liability since the tax tables are laid out in incremental steps of income.
