Comment by BillDemirkapi

I can assure you the answer clicked before my research ever started. Unless I am using web server software that responds with one site for multiple host names, you generally need to configure each host name that might be used with your web server as a different "site" (i.e Apache) / configuration. I could have simply edited my hosts file with hidusi[.]com pointing to my web server and created a separate site configuration to serve the hidusi[.]com domain with the second stage. What I was saying in my last response was that instead of using my hosts and having to create this new site configuration (or modify existing with an alias), I could just swap out the domain in the document and use my web server's current state without any additional modification required. It was simply more convenient to change a single domain rather than update my web server's configuration to support requests for the hidusi[.]com alias. There is no significance to using the original domain for serving the second stage, I think you all are all just overthinking it :)