Pretty cool stuff. I can’t speak for tungsten, but Molybdenum and Niobium are easy enough to machine that it only takes a couple weeks to get parts made. If you have an experiment planned in advance like different electrode lengths or diameters, the parts can be made in parallel.
It is not clear to me that 3D printing is producing “bulk” properties quoted for materials like tensile strength and conductivity. If 3D printing is as good a bulk it could be an interesting path forward.