Root Hosting is supported within STB Emulator.
Here is an easy to follow tutorial that will show you how to setup the STB Emulator for Root.
Go to Profiles in Settings
Tap Test portal to modify the existing profile or Add profile to start a new one
Tap Portal settings
Tap Portal URL
Enter your Portal URL, for Root it is http://root-hosting.ddns.net:25461/c/ and click OK
Ensure this Portal is active and go back to the home screen and you should be up and running.
Note: Code to access adult channels is 1234 OR 0000