I am not sure you are addressing the correct problem.   I am concerned about printing my account number (specific to that vendor) on my check, in the memo line.   NOT my bank account number.

For example, I want to pay my invoice to ABC company.  My account with ABC is #3456 so I need that number to appear on my payment to them, in the memo line.  I have added it to the Vendor Detail.

I am befuddled as to why this does not print.  Why would the field be on the Vendor Detail page if it is unusable??