It won't affect you. Technically, the pro-rata rule means that only 99.9907% of the conversion is tax-free, but the IRS uses three significant digits and rounds up, so 0.9999 should round up to 1.000. If you do another backdoor conversion in 2026, and assuming you contribute $7500 and convert $7500.65, the 65 cents will be rounded up to $1 and will be taxable next year.
