I applied 2000 for multiple K1s for my ex-wife for personal reason; she came to US more than once before we got married. We divorced in 2006. I applied K1 visa July/2007 for my fiancé. I asked for waiver and checked the international marriage site, and give the site URL, contact number. I was very worried but I got the NOA2 in normal timeline, no question asked.
Conclusion, just be honest and everything will be ok.
Hope this help people in similar situation.
Steve