I’ve only looked into this a bit, and I’m still unsure about what I can do at the moment with this. I’m fairly certain the other plugin can do this because it saves the file using an AJAX request in the background without reloading the page, but that also bypasses a lot of the core WordPress safety and security functionality with custom code to do that.
I’m not sure I want to explore that road yet. The main goal of this plugin has always been to stay as simple as possible, and focus only on replacing the core text field on the screen while still making use of as much core functionality as possible. This mainly also helps keep compatibility with additional plugins that might modify and extend the filesystem behavior as well (plugins handling theme edits while also updating content delivery networks for example).
It’s certainly possible, but would need to be done in just the right way. It would take some time to implement it.
