The issue has been resolved. The problem was the "Do not import
recipients into the database" dialog box was checked. We couldn't
uncheck it, that was the only difference between the production instance
and the sandbox I was comparing it to. To fix it, we changed the value
in the delivery form from true to false and, viola, the box could be
unchecked, we could change the destination mapping for the flowchart id
column and the OOTB template now works.