Correct, you are. The later parts in the article, though, specifically call out SFTP by name. Based on the other comments and some searches I did before hitti

Correct, you are. The later parts in the article, though, specifically call out SFTP by name. Based on the other comments and some searches I did before hitting that second part, I'm fairly certain they're actually using SFTP rather than FTPS, but having never actually touched the ACH system, I can't speak first-hand on that.