::After testing, I found that if you reorder the payment journal by description (which holds the vendor number) and then add sequential document numbers, the checks will print in alpha order. The journal appears to first look at sorting by document number and then line number. The system will replace the manually added document number with the check number after printing (which is line number order), but the print job should be in alpha order.
Don’t use the “Renumber Document Numbers” function as that numbers then in line number order. You need to manually enter document numbers in the print order. Painful if there are lots of checks, but it works.