Our Publish feature doesn’t use FTP, which makes it much simpler to develop and maintain.
In order to support FTP publishing we will need to build an entire FTP client. It will need to handle browsing remote folders, detecting and resolving file conflicts, storing login credentials securely, syncing said credentials between your Bootstrap Studio installs and dozens of other complications that we haven’t considered.
This is a lot of work for something that can be done with WinSCP. You can configure it to watch a local directory and automatically upload the new files to the remote (docs). Then you just export to the local folder.
For Linux and macOS you can mount the FTP server as a local directory and export there.