300-1800W power draw seems impressive! It looks like standard machines are using something on the order of 25kW while scanning, which certainly sounds prohibitive for less developed infrastructure.
Sounds like that's more about using a cryocooler to minimize the helium used-- but presumably that requires keeping the coils in a particularly hard vacuum to adequately insulate them.
There is some research towards operating at liquid hydrogen temperatures -- but hydrogen has its own logistical challenges.
Difficult stuff to store. I knew they needed cold gas, but liquid helium is crazy.