+1 for this feature. I use Textastic to modify scripts that end up being ran on a Raspberry Pi I have configured as a USB-Ethernet gadget for my iPad. Currently I am using Textastic’s WebDAV server mounted as directory with davfs2 on the Pi and it is a less than optimal solution. I would love to be able to just configure Textastic to upload files over SFTP on save with a “Cmd + S” shortcut from my Magic Keyboard. Having to go through an Upload UI (even if it ends up being a single button press) on every file change is a distracting workflow when working on anything other than small projects with low file counts.
Customer support service by UserEcho