Hi David,
that “recommended” means that this method is recommended over writing out the CSS code into an inline style in every page.
TablePress will do everything that’s necessary for this out of the box, so that you won’t have to mess with FTP clients or text editors.
If you really prefer a text editor for editing the CSS code, still don’t directly edit the file please, but go to the “Plugin Options” screen, copy the current CSS code from the text field, paste it into the text editor, make the desired modifications, and paste the modified code back into the textfield on the “Plugin Options” screen.
Only with this method, it is ensured that the minified versions of the CSS files are created correctly.
(The next version of TablePress will no longer have the “Use a file for storing and loading the “Custom CSS” code.” by the way. It will just assume that this is set, as the underlying requirements are fulfilled on most servers.)
Regards,
Tobias