I don't think anyone can give you a definite answer to your question - From the guide at the top of the forum:
QUOTE
(2) If you are abroad and intend to apply for a nonimmigrant visa or border crossing card, submit this application to the American Consul with whom you submit your visa or crossing card application, if instructed to do so by the Consul.
To me, this means you file the K1, and at your interview stage if you are denied then you would file the waiver - no way to know if you need the waiver or not until the Consulate says so at that point.