I was reading this topic
and very interested in the mobile forum too...
However it is very confusing that there must be a domain installed for this purpose.
Suggestion to authors is to avoid the sub-domain and use the cookie switch. Most of websites I am visiting from my smartphone, open mobile templates by default. There it is possible to switch to the desktop version, but rather no one does it on the smartphone. So if the desktop version is still switched on, the cookie is set, indicating the scripts should load the full version. If not, then the mobile version is loaded (but sure, for mobile device only).