Surely he has been coached on how to:
1. Listen to the question.
2. Answer the question.
3. Shut up.
I don’t believe the defense would subject him to cross examination without solidly believing he was ready to perform.
I’ve spent many, many hours on the witness stand in civil litigation. It’s EASY to screw up with even one or two words quickly!
If KR has a quick mind, and understands the basic principals like the 3 you enunciate, it may work out but it is a big risk.
Rittenhouse is very intelligent, especially as young people of that age go these days. He’s also far more in possession of himself and his wits than the stupid DA is.
If I were the judge in this case, I’d feel that the prosecution was insulting my own intelligence.