I may be mistaken but I believe they are still calling the browser MicroB.
so the file to edit is:
/home/user/.mozilla/microb/prefs.js

However, I can't get that to stick.
Thus see: http://browser-extras.garage.maemo.org/news/8/
Open this in the Application Manager http://browser-extras.garage.maemo.o...itcher.install (add the repo, then install the add-on)
Close any search toolbar widgets running, close the browser 2-3 times.
Then navigate to chrome://useragentswitcher/content/config.html

And a good list of user agents is at http://useragentstrings.com
perhaps pretend to be a iphone? You might have to play with it depending on what your cellular ISP allows.