I did some testing on this using Ubuntu and booting from the CD. I didn't bother installing it fully, as this was just for a test, but it looks there may be hope for those that want to mess with it.
In Firefox, I downloaded a plugin to change the user agent. This allowed the dish page to try and install it, but the install failed due to Firefox compatability.
Next, I downloaded Chrome and found another plugin called "User-Agent Switcher". This allows you to tell the browser to identify as windows, which tricks the Dish site. However, when installing the plug in, I get a message "NPAPI Plugins are not supported". A quick google search reveals that NPAPI plugin support ended in Chrome 42, and the current version is 44. So, it looks like you could make this work if you can get your hands on an older version of Chrome.
I'm probably going to dual boot the system, so I may play with this later when I have more time. Hopefully the info above will help others if they are trying this and we can all find a solution.