This is exciting but incredibly niche atm.

However, the "niche" is a non-trivial one--injection molds.

Machines already exist which deposit metal and also have a 3-axis CNC head that can then polish up the surface of that metal in the same envelope. This lets you directly print 3D molds with conformal cooling.

So, it doesn't matter if your machine is "slow" as long as it's faster than your alternatives for producing an injection mold.