I was just poking around my old haunts from college a bit, and was reminded that you can get ABS with chopped glass fiber reinforcement. It's available in pellet form (although I haven't dug to find a non-chinese supplier yet). So we could get it converted to 3mm welding rod format. I wonder how it extrudes.

[gonplastic.en.made-in-china.com]

We might pick up strength and lose some warping (or gain some! testing...), but I do expect higher rates of erosion in nozzles.