As of version 2.1.2, there are some speed shortcuts the optimizer will take by default if optimize is set to "none". However, if you are using "none" for optimize and you are planning to minify the built files after the optimizer runs, then you should turn set normalizeDirDefines to "all" so that define() calls are normalized correctly to withstand minification. If you are doing minification via the optimize option, then you do not need to worry about setting this option.