Elementor and Cloudflare integrate smoothly with each other, although there has been an issue with Rocket Loader in the past.
The issue was caused by Rocket Loader automatically changing the scripts to load asynchronously, which breaks the editor.
If this is causing you a problem, you can solve this by creating rules in Cloudflare:
For Elementor pages: Site URL/*elementor*For Elementor templates: Site URL/?elementor_library=*
To learn more about rules in Cloudflare please check their official documentation here.