Their whitepaper clearly demonstrates a profound lack of knowledge of thermal engineering. E.g. heat pumps are described as magical things.

They are literally planning to feed the radiators using a coolant like water and sensible heat at 35 degC to 5 degC. At 5 GW, you then need to be pumping 60 000 liters of water per second.

That's like a tenth of the Sacramento river, going through a 16 sq km array in space and hoping that nothing leaks.