I heard that Consulate (of course CIS office in China)

also accept a small number of staright-forward cases that are switched from K3 to DCF . That means that they may entertain US traveller as well. I am not sure the detailed procedure about it. Anybody who is interested in it may call the number above for further information. You may need to show them your 130 receipt and pay extra for a new 130. The final IV interview will be held in Guanzhou no matter where you file your DCF application. I have an impression that all five US consulates in China do DCF.