saiy4 Apache to OpenLiteSpeed and OpenLiteSpeed to Apache migrations could be done easily. Just uninstall the one you don't need and install the one you want to use. Switch is simple, as both support .htaccess files.
But if you have custom configurations of .htaccess on OLS or Apache, then you couldn't easily switch to NGINX, as NGINX uses it's own CONFIG which is different than .htaccess rules.
If it's a brand new server, and has no websites or no specific requirements for HTACCESS rules, then you can try NGINX too.
