Using SEF URLs on the WHM test link

I work at a web development company who sells Joomla websites to 100s of companies worldwide. Joomla allows us to enable SEF URLs by using an .htaccess. This works great on the standard domain during production. However, during development and staging, we would like to provide our clients access to the site to check it out and provide feedback without needing a hosts entry. Can we use SEF URLs when viewing the IP/~username/ URL or is it impossible to use SEF on the test link?

 

You say mod_rewrite rules don't "typically" work with mod_userdir so does that mean there is a way to do this somehow? The main reason we're trying to accomplish this is because we used to host our sites on the Rackspace cloud. On there, we would be automatically given a test URL for every site we create. This URL worked just like you were on the regular domain meaning SEF URLs worked well. We're just trying to see if we can recreate that convenience.