Personal Experience : 12262 hwh CSMT Duronto skipped R at 40 kmph.... It was an amazing moment to witness a train skip Raipur which is the halt for all trains.
My take is that Urkura Sarona section is used for mainly freight. If congestion in this section is low, Duronto passes through this section. Otherwise Raipur skip is definitely on the cards.
PS:I even have a clip of this train skipping Raipur from inside.