Yes, we do indeed support all PHP versions, including the latest PHP 7.3! PHP 7.X can potentially improve the speed of your sites significantly however, there are possible dangers; see below for more details.
How To Enable PHP 7.X
In your WPX Dashboard, there is a switch for the PHP version next to each website in that account. To change your PHP version, go to My Services (1) → Manage All Sites in this Account → Websites/SSL (2) and from here, select Settings (3) next to your chosen domain. You will then see the PHP tab (4) in the drop-down menu; select the PHP version (5) you prefer and select Save Changes when you're done;
Please note that PHP 7.X might not be supported by some plugins and themes you may use. Be sure to check your that websites are working smoothly after the PHP upgrade.
If you're unsure, check with the developers of your themes and plugins BEFORE enabling them inside your WPX admin panel. Otherwise, you can test it by switching to PHP 7.X and reverting back to an earlier PHP version if your site stops functioning correctly.