Hey Darian,
I had checked implementation of SearchCrawler and it seems to be tied to forms authentication where it takes user name and password and calls FormsAuthentication.GetAuthCookie(user, true); to get cookies for authentication and stores it in a container for future requests, however mvc apps is a separate app and I am afraid that custom index could be a solution in here (Marnix from TrueLime offers a bit more on crawlers in here)