speed up has nothing to do with the recent up-gradation of tracks between JTJ and KJM.It was running with a poor TT for decades.They just cut down the slack between TPT and KJM which they should have done much ago.Even 3 years ago, I have noticed Island reaching KPN by 3:35-3:40 am when HWH train gets late.Otherwise it will wait for HWH-YPR to overtake before KPN (In the case of early arrival),Now HWH-YPR timings got updated and TPTY-CMNR got updated.Ideally in the next iteration, they should change the timings from OTP on wards and allow this train to pass CBE before Cheran express by 10:35 PM , such that it should reach SBC by 6:00 am to 6:15 am with a slack of 30 min between BNC and SBC. This is very much possible