If you analyse the TT of Udyan, its crawling starts after GTL only. It runs at decent speed till GTL. I do not understand the logic of holding and delaying this train for more than 3 hours in a stretch of 190 Kms and allowing other trains to overtake them. SF covers GTL-YPR in 5hr 15 min, so a normal should cover this distance in max 6 hr 30 min. But it takes 8hr 40 min.
May be SWR wants to use this slot for daily passengers from DMM/ HUP to SBC. Otherwise, there is no reason for this much slack.