High temperature superconductors don't have to work at room temperature. As it doesn't require liquid nitrogen cooling, it's a lot easier to maintain and run.
If they're hitting 25T on a bore larger than a few cm then they're using supercritical 8K helium to cool ReBCO superconductors OR they have a super secret new superconducting material that the rest of the world doesn't know about and hasn't been used in other practical application (exceedingly unlikely, drunk uncle conspiracy theory tier).
does anyone know how this differ from outside temperature?