Hi JP. I also have been keeping a casual eye on 3d printing development and I think their strength may be in slightly different application.
The video you posted fistly while quite novel really doesnt show any real advantage in using 3d printing in this scenario. Practacally speaking the printed part in this application effectively just holds the glass bead in a focused position from the phones lens and given most phones are mass produced its likely more efficient to injection mould said part.
On the other hand very small scale specialist manufactured equipment that break an integral part where the OEM price to replace renders the product an economic write off is an area whete I see lots of potentual.