[neltnerb]

Extremely hard, the superconductors are a ceramic that is very brittle, it's quite hard to make a nice wire out of it. If a single break in a long length ruins the whole stretch then scaling up would be massively challenging, you can't just rely on melting and cooling to nicely even out issues during drawing a wire.

[theothermkn]

This exactly misses a significant feature of these new, high temp and high field superconductors: they are a mass manufactured flexible steel-backed tape. These are not the old ceramic superconductors.