Q: Do priests concelebrating a confirmation Mass with the bishop extend their hands during the prayer of confirmation?
A: It appears that I never corrected this post from 2016, when I gave the wrong answer: https://paulturner.org/handlayings-at-confirmation/ .
Only priests who will confirm some of the candidates extend their hands with the bishop. If the bishop is confirming alone, the priests do not participate in the prayer of confirmation, nor in the act of confirmation.
Look at Order of Confirmation 8, 9, 24 and 25.