You can create a dev site and import any template there, then with the help of the import functionality of Elementor you can copy some specific blocks (e.g. footer) and move them to the main website, more details are here: https://elementor.com/help/template-library/
Devsite – also called a Staging platform where you can test issues, enable/disable features/plugins thus such changes will affect the main site. The below article will help you to create it: