> if you could grow a good single crystal of LK-99, it seems as if the superconductivity might only occur along one crystal axis: put crudely, you'd see superconductivity if you hooked your wires to two particular opposite faces of said crystal, but not to the others! Crystalline grain boundaries are already known to be a big deal in the efficiency of existing superconducting materials, and this would mean that polycrystalline samples of LK-99 would be pretty unfavorable to demonstrating robust effects.

I think this means production of usable superconducting masses will be tricky, if its even possible.

So... Probably on the longer side? Time will be needed to figure out how to make it macroscopically, or discover a similar compound thats easier to produce in bulk.

But once wire, coils, high purity samples and such start getting sold, I think the adoption would be very quick.