The problem went away (maybe cmp restart was needed?) Anyway, it works now! I'm definitely buying it now.
So, I know about save_before_upload settings - it's useful, but I think it'd nice to have a setting (it can be local to project) to upload file on standard save operation (ctrl+s), so one doesn't have to use the new shortcut to upload files. Of course, I don't know what others think - maybe I'm the only one.