We've read the rules.
Where it says "We currently allow one auction, be it a normal or dutch auction, to be placed in a single category. Do not place the same item in many different categories." you have to assume "auction" = "listing" as we can't find anywhere that suggests otherwise & the 2 terms are seemingly randomly interchanged throughout the rules.
Again just to point out what already happens. You can currently list at 2 different prices - everybody that does a bid or BIN on a single listing does this all the time ?
All we want to do is split these out into 2 different listings / auctions (one with a bid option, one without
even if it means putting the same BIN on both listings