Just tried your plugin on a smaller site.
Because there was detection for WP Supercache, I needed to delete the plugin as well as the wp-config.php line that configures the location directory for wp-supercache.
That line looks like this on my local machine:
define( 'WPCACHEHOME', '/Users/MartinC/Sites/gaj/wp-content/plugins/wp-super-cache/' ); //Added by WP-Cache Manager
Further, you could also look to exclude the contents of the cache directory as well which is typically at:
All in all, what a cool plugin so kudos and thank you