Hello,
Thanks for the question. If you want to see what's loaded on your server, you can use PHPINFO.PHP to verify it. To use PHPINFO.PHP, go to a browser like and enter your URL followed by phpinfo.php as per the example below:
http://example.com/phpinfo.php
You will then see a list of the items that are loaded. In this case, you're looking for SimpleXML , so after running the URL (as per above), use ctrl-f (to find - or on an Apple computer: command key + f) and search for "SimpleXML". This will show you that SimpleXML is loaded on your server and it is enabled.
If you (or anyone else) needs to create the phpinfo file, check out this tutorial.
So, the answer to your question is "YES" it is supported, loaded and enabled. I also loaded a WordPress plugin that required SimpleXML and it works fine.
If you require any further assistance, please let us know.
Regards,
Arnel C.