It is insane. The flagpole glitch he was using on every level just a few years ago was considered prohibitively difficult to be included in every level in a world record push. He just nailed every single one of them, that's why after the 2nd or third one he and the chat started going nuts.
I forget what it was, there was a big world record by darbian a few years ago like 4:56 and a lot of people then thought it'd be impossible to get this close to the TAS record. 5 or so years later we're here.