I think it's pretty telling that this guy using his knowledge of electrostatics as a shield, when the experimental failure of previous reactionless drives have come down to magnetism, especially interaction with the Earth's magnetic field. NASA has a excellent mu-metal shielded vacuum chamber for debunking reactionless concepts. Stick it in there, and let's talk if it shows some results.

https://arstechnica.com/science/2018/05/nasas-em-drive-is-a-...