"proxy_media": true
"strip_exif": true

To get work "strip_exif" you have to install dependence ffmpeg + ImageMagick. It removes all meta-data from your uploaded media files before they posted.
And what "proxy_media" does is incredible, it opens every single media file get proxied by your server, avoiding leaking of your real IP from client.
Thank you @grunfink@comam.es for these two incredible features that should be enabled by default.