Beside the obvious diurnal health impacts, solar PV doesn't work well when shaded and relies quite a bit on diffuse light to keep the array producing during those edge of day times when it is economically hard to make the modules spread out enough to avoid direct sun shading. Pointing reflected beams from arbitrary directions in the sky turns out to be very likely to create unusual shade lines that will render the light nearly unusable by the panels.

Then of course since they are planning to locate the reflectors in high-angular-velocity low earth orbit even if the angles are briefly conducive to power conversion it won't last very long and then some fossil fuel generator is going to have to bobble their throttle to fill in the gaps.... which is the worst possible scenario for using solar power (equal amounts of fossil generation as PV needed so no displacement).