it is time consuming for Pune, not the train ;)
Pune, like many other major junctions throught country sees hell lot of trains and having each train undergo LC would increase the halt of many trains from 10 to 20 minutes, and Pune with its 6 platforms (unlike many others which have 10 or 10+) won't be able to cope with it. hence avoided.
once Pune-DD gets electrified some trains can undergo change there (especially those on MMR route as they undergo LR there). but otherwise it is difficult.