Speaking of policies/best practices for such a DAC comparison, I strikes me that knowing which DAC you're listening to is a major flaw.Policies don't exist for contests? My general understanding is that every game or contest has specific rules determined in advance to make the contest fair to all competitors.
I know blind listening is anathema to many audiophiles. I remember when I asked the first audiophile I ever met (a dealer), "how can you be sure your bias's, conscious or un-conscious, aren't influencing your conclusions?" -- he went into a emotional tirade against "objectivists", etc, etc!
I think if you really want to remove the variable of bias, particularly when there is a 1300 lb gorilla like the Wadax in the mix, you have to listen without knowing which component you're listening to.