Right, sorry. The full plugin can still be run without Steam (although doing nothing) on compatible OSes (Windows and some versions of Linux), but if you're specifically publishing a non-Steam version it's still recommended that you use the stub instead of the full plugin. This allows the end-user to rebuild the stub for their system if the prebuilt stub (the one you would include in your distribution) does not run (e.g., versions of Linux using different core libraries, other unsupported OSes).