Hello,
https://xstore.helpscoutdocs.com/article/100-how-to-speed-up-my-website – yes, we are using WP Rocket. We do not declare compatibility with the jetpack, because did not test this plugin with our theme officially, some of our customers use this plugin, but some disabled it due to errors that occur (we do provide support for this plugin). 3rd party plugins men all plugins that do not come bundled with our theme – https://xstore.helpscoutdocs.com/article/36-included-plugins
Regards
