You see, my guess for how the crystal "works" is that it draws massive amounts of light energy using powerful artifact pylons on the surface. The Crystal is not a "reflector" of the system's star in the sense of a giant mirror, but in the sense of a giant magic object that redistributes light (and thus heat). An "eclipse" of the Azure Sun would be caused by the physical hub gathering sun-energy at the surface going through some short "cool-down" period, and such.