Module doesn't work when site isn't accessed through a URL that is not in DNS

We have a somewhat contrived example but let me try to explain...

Lets say we have a site on 3 different environments: dev.mysite.example.org, stg.mysite.example.org, prod.mysite.example.org. Once the site goes 'live', in dns the site will work just as mysite.example.org, but before then testers have to go to one of the 3 'environmental' urls.

In such a scenario, can this module work by calling the static_404_generate function via drush? If you invoke drush with -l prod.mysite.example.org, the 404 page is generated that contains links (like the css, js, etc) that contain http://prod.mysite.example.org. If, on the other hand, you call drush with -l http://mysite.example.org, the 404 generate command will fail until the site goes into DNS.

We can't figure out a solution that will allow this module to work for us in all possible scenarios.