How to disable UserProfile table access with ASP.NET MVC4 custom membership

How to disable UserProfile table access with ASP.NET MVC4 custom membership

I am trying to use ASP.NET MVC4, while keeping the user data in NoSQL data
store.
I am implementing my own membership class, supporting both OAuth and forms
authentication, inherited from ExtendedMembershipProvider.
At some point, I noticed that the local data store 'UserProfile' table is
being filled out with OAuth users. Seems like the default generated code
in AccountController::ExternalLoginConfirmation is manipulating that table
directly.
I found an article on implementing a custom Profile Provider.
Yet this seems a huge overkill to my needs, since I can manage user
profile in the application.
Is there a clean way to disable to "Profile" feature? Is it legitimate to
edit the controller code, or it is rather hiding the real problem? If I
must have the "ProfileProvider" on my own, what is the mininal set of
methods I can implement to get it "happy"?
Thanks a lot.