I notice that Desktop Metal doesn't show their oven in the video. That's the big, expensive, somewhat hazardous unit. "Easily swappable aluminum gas canisters ... safe to use on the shop floor" says the data sheet.[2]

Wazer, the low-end water jet cutter that's still stuck at "pre-order", has a similar problem. They're trying to make a somewhat messy industrial process less messy. There's some hand-waving involved. You end up with a sludge that's a mixture of water, shattered garnet, and whatever you're cutting. They gloss over what you have to do to dispose of that.

[1] https://www.youtube.com/watch?v=B9VOwqtOglg [2] https://desktopmetal.s3.amazonaws.com/Studio-office_friendly...