@mick he does plenty of unstructured appearances without a teleprompter just fine. Debates are their own thing with a lot of unique characteristics - for example, his team’s got to work on his attitude when it’s not his turn.
I’d also say they’ve got to be more disciplined about sticking to punchy three item lists on topics, but I’m an extremist on that point, mainly because of my own struggles with stuttering and filler.
Every flaw I saw was a rehearsal failure.