That sounds like a valid argument. I hadn’t realized that deductions are effectively multiplied by the annualization factor. However, it is noteworthy that the standard deduction is not annualized. Schedule AI may be a compromise solution handling a variety of different cases. It seems to work quite well when income and deductions are spread evenly across the four quarters. It may not work quite as well when income and deductions are concentrated in the early quarters. The schedule also incorporates a tax that is reduced by the applicable percentage for each quarter on Line 20. In the end, everything evens out in the final two quarters.
Thanks for the reply.