Was this issue fixed? I'm trying the latest version and have tried both Purge Modes, but I'm unable to see it removing an files in my cache folder when clicking the Purge Entire Cache button. This is on a new site where I'm updating a theme fairly often. Without the ability to purge the cache after updating the theme, I have to login and manually remove the cache folder.
I verified the RT_WP_NGINX_HELPER_CACHE_PATH was set correctly and I believe the nginx config files are setup properly for fastcgi_cache_purge.