Can I Use WP Rocket With Siteground's SuperCacher?

Yes! 

WP Rocket is compatible with all 3 levels of SiteGround's caching - Static Cache, Dynamic Cache (NGINX) and Memcached.

When you activate the Dynamic Cache (NGINX) feature of SuperCacher, this will automatically deactivate WP Rocket's page caching feature, but you will still benefit from our other performance optimizations such as browser caching, LazyLoad, minification etc. 

So, if you want to use WP Rocket's page caching, just disable the Dynamic Cache in SuperCacher. 

Activating Memcached in SuperCacher does NOT disable WP Rocket's page caching. 

When you purge the WP Rocket cache it also purges your SiteGround cache, and vice versa. 

We encourage you to test for yourself which combination of caching works best for yourself. Learn how to correctly measure your site's speed by following our guide: 
http://blog.wp-rocket.me/correctly-measure-websites-page-load-time/