Currently Vanilla-WP runs with WP-Super-Cache enabled, and my abandoned Database Cache disabled. The fun part of WP-Super-Cache as caching plugin is, it allows the usage of plugins. Yes, a plugin for a plugin 🙂 . One of those plugins is WPSCMin, by Joel Hardi.

WPSCMin for WP-Super-Cache utilizes the Minify library in PHP, minifying the generated supercache files. Using this, your WP-Super-Cache supercache files are smaller, and delivered to clients faster. For every supercache file kilobytes of data and size are knocked off thanks to the compression process.

From my Windows command prompt, before and after enabling WPSCMin:

Directory of \path\to\wp-content\cache\supercache\www.vanilla-
  wp.org\save-mysql-database-cache-wordpress

  06/28/2016  11:02 AM    <DIR>          .
  06/28/2016  11:02 AM    <DIR>          ..
  06/28/2016  11:02 AM            39,131 index-https.html
  06/28/2016  11:02 AM             9,612 index-https.html.gz
Directory of \path\to\wp-content\cache\supercache\www.vanilla-
  wp.org\save-mysql-database-cache-wordpress

  06/28/2016  11:05 AM    <DIR>          .
  06/28/2016  11:05 AM    <DIR>          ..
  06/28/2016  11:05 AM            36,012 index-https.html
  06/28/2016  11:05 AM             8,972 index-https.html.gz

This is not a real big difference, but saving tens of kilobytes is possible.

If you’d like to know more about how to Minify WP-Super-Cache files:

Minify WP-Super-Cache HTML cache files: WPSCMin a WP-Super-Cache plugin