Would it be better to use a "super" neutral wire of sufficient gauge than all the separate neutrals? You'd need a terminal bar insulated from the box to land all the neutrals to connect to the superneutral. But if there are circuits from both sides of the 110/220 line in there (likely if it was a panel) currents from one side would get shared at the bar in this box instead of having to travel to the new circuit breaker panel serving this box on one neutral and back again on another neutral wire. Less heat and wire in the big conduit that I presume is feeding to the main panel.