Thanks for this insight.
As near as I can tell, the number ($4,000) for 2021 is not able to be changed since there was (apparently) carry over from last year (and probably from several years before). I assume the amount left in the "Prior Year Unused Amounts" column (for the "College Savings Accounts (529)" window) will be reduced by $4,000 when I get ready to do my 2022 taxes.
