Every time I see this I think, 'Neat, but what would I actually do with it?'
Nothing. I got nothing.
use your imagination man
you can literally wrap concrete structures with resins and cloth to make certain areas earthquake-proof, so something like this 3d extruder might prove useful in its own right... like using derivatives of this technology to immediately make repairs, reinforce objects. think of drawing trusses or just profile tracing something to increase load-bearing capacity
creating flexible/openair casts for broken/sprained limbs, injectable woundhealing/bloodclotting or diy dental casting
what i would really love to see is something which 3d prints using water at below-freezing, that would be so fun and cheap i imagine