Assigning a mobile theme automatically on registration

I've been testing the module and I find that by default when editing a user profile, the 'mobile theme' isn't selected via a radio button. To me this means that the user won't see the mobile version when viewing the site on a mobile device.

Does the module require a user visit his/her profile and select a theme to view on mobile devices before it actually works? This seems counter-intuitive to me -- while I can see this being helpful if you have multiple mobile themes -- for just 1 theme, I'd like it to default to the mobile theme without the user having to intervene at all.