WIth that version of FFCore you need to submit the job as either a Manifest in which multiple rows are part of the same job or via JMF adding multiple files to the RunList.
Yes this is also there in the 18.104.22.168.
In addition, you can zip the files and they will be submitted as a job group which can be joined into a single PDF. The files will be joined in alphabetical order.
I guess this also goes without saying but the Submit Job interface will also create a job group when multiple files are uploaded and submitted as a single job.