I think electrochemical polishing[1] of the discs on both faces could be done without killing anyone. Since everything happens in a liquid, no vapors should evo

I think electrochemical polishing[1] of the discs on both faces could be done without killing anyone. Since everything happens in a liquid, no vapors should evolve. A VERY flat surface might greatly increase the bounce. A surface coating of BAM[2] might also help, by increasing the hardness, and lubricity. I think there's a lot of room to go in increasing the hang time of the bouncing bearing. [1] https://en.wikipedia.org/wiki/Electrochemical_grinding https://en.wikipedia.org/wiki/Electrochemical_grinding [2] https://en.wikipedia.org/wiki/Aluminium_magnesium_boride https://en.wikipedia.org/wiki/Aluminium_magnesium_boride