I got the "published fare" rule straight from the horse's mouth when I was on the phone with a Delta rep while booking my itinerary. She put me on hold for 20 minutes and supposedly had an extensive conversation with the "fare desk" or something about why my award was coming out at 85K rather than 60K. Turns out it was because I was not going through either of the two connections that were published from origin to destination.

The lesson I am learning from this is that there is absolutely no way to know if an award trip with stopovers is bookable until you call and see if the individual Delta rep will book it for you or not. So far no one has proposed a definitive ruling on stopover allowance. I do not mean that statement to be insulting, but rather to highlight that there is no rule to follow when building an itinerary, no way to know with certainty whether an itinerary is valid until one calls and tries to book it.