Of TII i can't talk to much, because i don't saw a real rehearsal, without heavy edition and only the best vocals and best moments.
In 30 aniverssary he only sangs the J5 Medley and the firts verse of the way you make me feel (slow a ralentized)
But songs like Billie Jean with playback, you can hear him clearly out of breath, on Beat It he sounds a bit tired on the live part.
I would like hear him sang more live on the firts show, althought he was high, some people says that show was better than the second show, vocal talking sounds better and not tired like the second show, where he dance a lot and maybe this is the reason due he was out of breath, thing that not happen in the History Tour, where he dance a lot, but when he starts to sang live he is not are out of breath.