YBCO is used in cutting edge Tokmak fusion reactors like SPARC. I'm not sure how an 18% increase in allowable temperature would change how much closer you could move the magnets to the plasma. Squinting at Figure 1 in [0], it seems possible you could get significant increased in Q from 18% increase in temperature.

[0]: Overview of the SPARC tokamak. Journal of Plasma Physics https://www.cambridge.org/core/journals/journal-of-plasma-ph...