Your comments

The current implementation of save_on_focus_lost is sufficient for some, but not for all people. I like to see another option that saves all documents when Sublime loses focus, similar to how TextMate behaves.

The problem with the current implementation is, that it saves to often. For example: I develop Python code an the server automatically reloads if a file changes. When I'm editing a project with multiple files, I will often switch between files (to look things up or write new functions), but some files might be in a broken state. When I switch to another file with save_on_focus_lost my server will reload and crash.

I hope this makes it a bit more clear why a second save on focus option is necessary.