For EmDrive to work, Lorentz invariance must be seriously broken, to cut short. That’s not to say I’m against such possibility, or anisotropy of physics laws in general, but creation of Unruh effect-driven engine under mundane Earth conditions, deep in the gravity well, seems very far-fetched project, on par with detection of gravitational waves using Weber’s antennas in 1970s. (The latter was laughed to smithereens at, of course.)