That cooling system is … aggressive. 110m^2 of radiator to dissipate 120kW average heat. That’s about 1.1kW/m^2, which works out to very close to 100C at the radiator under absolutely perfect conditions (absolute zero ambient temperature, emissivity 1, no adverse geometric effects).

Radiating into 300K ambient, it’s 134C. (300K ambient is about what you get if the sun is visible or if a large fraction of what the radiator can see is the Earth.)

You can slightly fudge the 300K case with a spatially or specially selective system, which would add weight and complexity. (Well, you can’t get rid of the problem of the Earth being warm by spectral selectivity — it’s the same spectrum as the radiator.) You cannot fudge the absolute zero case — the Stefan-Boltzmann law is extremely unforgiving. [0] And you need some headroom for the system that gets the cooling fluid to the radiator.

The thermal qualification temperature of an H100 is 87C and the associated HBM is 95C.

So I don’t see how this can work short of using higher-temp chips. I have no idea how SpaceX expects to source any such thing in any meaningful volume.

[0] This includes heat pumps. A heat pump makes it worse.

I assume the radiators will be in the shadow behind the solar panels and never facing the sun. That's seems like the easiest quick win.