Reply To: Why do we remove teffilin before Musaf on Rosh Chodesh?

There is also an inyan that if the baal tefilla is wearing them on chol hamoed PESACH only, he waits until after hallel to remove them. It’s likely because of tircha d’tzibbura, which would not be as pressing on chol haMoed Sukkos, when there is already a break before hallel, to permit people to bentsch esrog.