How do I merge but not minify my CSS files, or only minify and not merge my CSS files?

You can merge your CSS files without minifying them — or vice-versa — by doing the following:

1. Go to WP-Optimize > Minify > CSS
2. Scroll to the “CSS options” section
3. Uncheck the “Enable minification of CSS files” or “Enable merging of CSS files” checkbox, depending on your needs:

4. Click ‘Save settings’