One advantage is that the raw supplies are inherently able to withstand the flight up there, so no investment has to be made into over-engineering the parts to survive being shaken to pieces by a rocket.

The question I had is how the polymers they're using behave in vacuum; they'll almost certainly outgas like crazy. How strong/durable do the parts remain after a given amount of time in space? What about UV light? I'd love to see them do some materials testing before sending an expensive printer up only to find out the parts don't last long enough to be useful.

This assumes that we have no control over where the heat goes. If, on the other hand, we can direct the heat into something else, then the ambient temperature won't get nearly so high. That is, after all, why you have a heat sink on your CPU.

Still, I agree with being a bit skeptical. I think I read somewhere that he claims to use one of these as a glorified space heater. I'd bet a room full of these would get pretty warm in that case... I'd be interested to know where all that energy is going.