Well from what I hear, a lot of people have filed their AOS after their I-94 expires for K1 visa for various reasons; economic, marriage dates, certain paperwork, etc. Getting married and filing the I-485 before the 90 days its actually quite difficult and if you do manage to get that done kudos, but the majority I believe are out of status. My reason is mostly economical but regardless, your input helps! Thank you!