My son's school uses a time out method.
I think for intents and purposes, may be harder to try at home, then again..,
Teacher notices child about to reach disruption or overwhelming agitation or however they do this..
Gently say students name, they then stay in same room, but to a designated area. Sit, close eyes, count backwards from 10. When ready to feel ready to participate join the class. My youngest, had twice, then no more. Taught him a regrouping skill, imo.
Perhaps a variation?
Kids process traumas in different forms. Punishment comes accross rejecting of themselves. Not that there needn't be consequences and boundaries. They don't give much info about raising kids who have that type of stress. (Sort of frustrating, imo...)