Up until school kicked back into session in August, I was an elevated assistant instructor in my home dojo two days each week. I say "elevated" only because there were numerous times when Sensei trusted me to lead the classes on my own if something prevented him from being there, ala family emergency.

Anyway, we tried to steer clear of using calisthenics as punishments, because we wanted people to enjoy workouts rather than associate them with punishment. But there were times, numerous times, actually, when being ADHD didn't exempt a kid from holding a straddle stance with a bo staff over their shoulder for a few minutes.

Our other methods were just things like having the student sit at the back during class, or if they were lined up and not showing respect, to stand at the back, regardless of rank.
Regards, Steve 4th Kyu - Yoshukai Karate-do