Some front load stuff is "red flag" stuff, things like prior relationships, knowing family in states, or elsewhere, if prior relationship was another immigrations case? Other things for K-1 are travel info, if you traveled to China to meet, evidence of when and how many trips prior to petition filing is required, if met in states, as in perhaps Chinese citizen working or here as a student, then evidence of them being here. K-1 requires evidence of being together sometime within 2 year of filing, pictures together without dated evidence won't do. In addition to providing the pages of chats and emails, I also included many things proving I went to China to meet her. I included scans of boarding passes, my passport with visa entry and exit stamps, my itinerary, store receipts, and train tickets. I feel that I have included everything they asked for and look for. Crossing my fingers.