Hello, I just ran the WPEngine PHP 7.0 Compatibility plugin and noted just this one issue in Enfold (same issue in two files):
4207 | WARNING | The use of function split is discouraged from PHP version 5.3; use preg_split instead
/wp-content/themes/enfold/config-layerslider/LayerSlider_old/helpers/phpQuery.php
/wp-content/themes/enfold/config-layerslider/LayerSlider/helpers/phpQuery.php
Thanks