You can increase the security of YourSites further but at the cost of making the addition of sites to your YourSites server a little bit more complicated.
In all these cases you will need to add your sites to YourSites manually and downloading and installing a site specific client package. The main functionality of YourSites will work perfectly on such a restricted server.
We love every single one of our users, without you YourSites simply couldn't happen! So we would love a review at the Joomla! JED so we can let others know about us too, please take a minute to write a review:
If you feel you have something negative to say, we would implore you to speak to us first, as we really really don't want anyone to be unhappy!