I notice they went into the possibility of printing metals and other materials, I wonder if the metal clays used in some metal printers could be adapted to cure in vaccuum, or if ceramics in general behave similarly in vaccuum as they do in atmosphere. If so, "firing" a ceramic print could be as simple as sending it out of the airlock and exposing it to sunlight. With ceramic printing we already have both metal, nonmetal materials as well as inherently strong and heat resistant properties of both, and a lack of toxic gasses from the printing process.

Also, Niki mentioned that there is no natural convection in zero-g, which kind of blows my mind a bit, though it makes complete sense.