Change theme for browser type?

I’m afraid that is, like this thread, a bit too specialized a request to work on at this time:
http://ww.wp.xz.cn/support/topic/multiple-themes-using-custom-fields

I do appreciate your continuing interest in the plugin.

Perhaps in the future I can come up with a more generalized design that allows filtering by every imaginable type of metadata. Some of which, of course, open up other issues. Such as a recent request to allow each Post/Page author to choose their own Theme.