Looking through the code of the plugin it seems the answer is “no.”
So, can it be added? Seems simple enough–Add a filter hook for “user_contactmethods” to include a new “Google Authentication Email Address” field on the user profile. Then, in the plugin check if that field contains data. If it does, use that value when authenticating, if not, fallback to using the standard email address.
You could even include a plugin setting on whether or not you want this field added to the profile page so regular users of the plugin wouldn’t need to be bothered by this addition.