You could probably use significantly less coolant if you're using heat pipes. The coolant is mainly gaseous and only a small mass remains liquid during the cycle
There is a certain amount of energy you need to move from the chips to the atmosphere or to the geology, and a liquid coolant vs a gaseous coolant will make a BIG difference in how much of that heat you can move. I don't know why I am arguing, putting a data center on the moon is dumb as hell.